| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/num-traits-0.2.15/src/cast.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>cast.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../num_traits/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../num_traits/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| <span id="523">523</span> |
| <span id="524">524</span> |
| <span id="525">525</span> |
| <span id="526">526</span> |
| <span id="527">527</span> |
| <span id="528">528</span> |
| <span id="529">529</span> |
| <span id="530">530</span> |
| <span id="531">531</span> |
| <span id="532">532</span> |
| <span id="533">533</span> |
| <span id="534">534</span> |
| <span id="535">535</span> |
| <span id="536">536</span> |
| <span id="537">537</span> |
| <span id="538">538</span> |
| <span id="539">539</span> |
| <span id="540">540</span> |
| <span id="541">541</span> |
| <span id="542">542</span> |
| <span id="543">543</span> |
| <span id="544">544</span> |
| <span id="545">545</span> |
| <span id="546">546</span> |
| <span id="547">547</span> |
| <span id="548">548</span> |
| <span id="549">549</span> |
| <span id="550">550</span> |
| <span id="551">551</span> |
| <span id="552">552</span> |
| <span id="553">553</span> |
| <span id="554">554</span> |
| <span id="555">555</span> |
| <span id="556">556</span> |
| <span id="557">557</span> |
| <span id="558">558</span> |
| <span id="559">559</span> |
| <span id="560">560</span> |
| <span id="561">561</span> |
| <span id="562">562</span> |
| <span id="563">563</span> |
| <span id="564">564</span> |
| <span id="565">565</span> |
| <span id="566">566</span> |
| <span id="567">567</span> |
| <span id="568">568</span> |
| <span id="569">569</span> |
| <span id="570">570</span> |
| <span id="571">571</span> |
| <span id="572">572</span> |
| <span id="573">573</span> |
| <span id="574">574</span> |
| <span id="575">575</span> |
| <span id="576">576</span> |
| <span id="577">577</span> |
| <span id="578">578</span> |
| <span id="579">579</span> |
| <span id="580">580</span> |
| <span id="581">581</span> |
| <span id="582">582</span> |
| <span id="583">583</span> |
| <span id="584">584</span> |
| <span id="585">585</span> |
| <span id="586">586</span> |
| <span id="587">587</span> |
| <span id="588">588</span> |
| <span id="589">589</span> |
| <span id="590">590</span> |
| <span id="591">591</span> |
| <span id="592">592</span> |
| <span id="593">593</span> |
| <span id="594">594</span> |
| <span id="595">595</span> |
| <span id="596">596</span> |
| <span id="597">597</span> |
| <span id="598">598</span> |
| <span id="599">599</span> |
| <span id="600">600</span> |
| <span id="601">601</span> |
| <span id="602">602</span> |
| <span id="603">603</span> |
| <span id="604">604</span> |
| <span id="605">605</span> |
| <span id="606">606</span> |
| <span id="607">607</span> |
| <span id="608">608</span> |
| <span id="609">609</span> |
| <span id="610">610</span> |
| <span id="611">611</span> |
| <span id="612">612</span> |
| <span id="613">613</span> |
| <span id="614">614</span> |
| <span id="615">615</span> |
| <span id="616">616</span> |
| <span id="617">617</span> |
| <span id="618">618</span> |
| <span id="619">619</span> |
| <span id="620">620</span> |
| <span id="621">621</span> |
| <span id="622">622</span> |
| <span id="623">623</span> |
| <span id="624">624</span> |
| <span id="625">625</span> |
| <span id="626">626</span> |
| <span id="627">627</span> |
| <span id="628">628</span> |
| <span id="629">629</span> |
| <span id="630">630</span> |
| <span id="631">631</span> |
| <span id="632">632</span> |
| <span id="633">633</span> |
| <span id="634">634</span> |
| <span id="635">635</span> |
| <span id="636">636</span> |
| <span id="637">637</span> |
| <span id="638">638</span> |
| <span id="639">639</span> |
| <span id="640">640</span> |
| <span id="641">641</span> |
| <span id="642">642</span> |
| <span id="643">643</span> |
| <span id="644">644</span> |
| <span id="645">645</span> |
| <span id="646">646</span> |
| <span id="647">647</span> |
| <span id="648">648</span> |
| <span id="649">649</span> |
| <span id="650">650</span> |
| <span id="651">651</span> |
| <span id="652">652</span> |
| <span id="653">653</span> |
| <span id="654">654</span> |
| <span id="655">655</span> |
| <span id="656">656</span> |
| <span id="657">657</span> |
| <span id="658">658</span> |
| <span id="659">659</span> |
| <span id="660">660</span> |
| <span id="661">661</span> |
| <span id="662">662</span> |
| <span id="663">663</span> |
| <span id="664">664</span> |
| <span id="665">665</span> |
| <span id="666">666</span> |
| <span id="667">667</span> |
| <span id="668">668</span> |
| <span id="669">669</span> |
| <span id="670">670</span> |
| <span id="671">671</span> |
| <span id="672">672</span> |
| <span id="673">673</span> |
| <span id="674">674</span> |
| <span id="675">675</span> |
| <span id="676">676</span> |
| <span id="677">677</span> |
| <span id="678">678</span> |
| <span id="679">679</span> |
| <span id="680">680</span> |
| <span id="681">681</span> |
| <span id="682">682</span> |
| <span id="683">683</span> |
| <span id="684">684</span> |
| <span id="685">685</span> |
| <span id="686">686</span> |
| <span id="687">687</span> |
| <span id="688">688</span> |
| <span id="689">689</span> |
| <span id="690">690</span> |
| <span id="691">691</span> |
| <span id="692">692</span> |
| <span id="693">693</span> |
| <span id="694">694</span> |
| <span id="695">695</span> |
| <span id="696">696</span> |
| <span id="697">697</span> |
| <span id="698">698</span> |
| <span id="699">699</span> |
| <span id="700">700</span> |
| <span id="701">701</span> |
| <span id="702">702</span> |
| <span id="703">703</span> |
| <span id="704">704</span> |
| <span id="705">705</span> |
| <span id="706">706</span> |
| <span id="707">707</span> |
| <span id="708">708</span> |
| <span id="709">709</span> |
| <span id="710">710</span> |
| <span id="711">711</span> |
| <span id="712">712</span> |
| <span id="713">713</span> |
| <span id="714">714</span> |
| <span id="715">715</span> |
| <span id="716">716</span> |
| <span id="717">717</span> |
| <span id="718">718</span> |
| <span id="719">719</span> |
| <span id="720">720</span> |
| <span id="721">721</span> |
| <span id="722">722</span> |
| <span id="723">723</span> |
| <span id="724">724</span> |
| <span id="725">725</span> |
| <span id="726">726</span> |
| <span id="727">727</span> |
| <span id="728">728</span> |
| <span id="729">729</span> |
| <span id="730">730</span> |
| <span id="731">731</span> |
| <span id="732">732</span> |
| <span id="733">733</span> |
| <span id="734">734</span> |
| <span id="735">735</span> |
| <span id="736">736</span> |
| <span id="737">737</span> |
| <span id="738">738</span> |
| <span id="739">739</span> |
| <span id="740">740</span> |
| <span id="741">741</span> |
| <span id="742">742</span> |
| <span id="743">743</span> |
| <span id="744">744</span> |
| <span id="745">745</span> |
| <span id="746">746</span> |
| <span id="747">747</span> |
| <span id="748">748</span> |
| <span id="749">749</span> |
| <span id="750">750</span> |
| <span id="751">751</span> |
| <span id="752">752</span> |
| <span id="753">753</span> |
| <span id="754">754</span> |
| <span id="755">755</span> |
| <span id="756">756</span> |
| <span id="757">757</span> |
| <span id="758">758</span> |
| <span id="759">759</span> |
| <span id="760">760</span> |
| <span id="761">761</span> |
| <span id="762">762</span> |
| <span id="763">763</span> |
| <span id="764">764</span> |
| <span id="765">765</span> |
| <span id="766">766</span> |
| <span id="767">767</span> |
| <span id="768">768</span> |
| <span id="769">769</span> |
| <span id="770">770</span> |
| <span id="771">771</span> |
| <span id="772">772</span> |
| <span id="773">773</span> |
| <span id="774">774</span> |
| <span id="775">775</span> |
| <span id="776">776</span> |
| <span id="777">777</span> |
| <span id="778">778</span> |
| <span id="779">779</span> |
| <span id="780">780</span> |
| <span id="781">781</span> |
| <span id="782">782</span> |
| <span id="783">783</span> |
| <span id="784">784</span> |
| <span id="785">785</span> |
| <span id="786">786</span> |
| <span id="787">787</span> |
| <span id="788">788</span> |
| <span id="789">789</span> |
| <span id="790">790</span> |
| <span id="791">791</span> |
| <span id="792">792</span> |
| <span id="793">793</span> |
| <span id="794">794</span> |
| <span id="795">795</span> |
| <span id="796">796</span> |
| <span id="797">797</span> |
| <span id="798">798</span> |
| <span id="799">799</span> |
| <span id="800">800</span> |
| <span id="801">801</span> |
| <span id="802">802</span> |
| <span id="803">803</span> |
| <span id="804">804</span> |
| <span id="805">805</span> |
| <span id="806">806</span> |
| <span id="807">807</span> |
| <span id="808">808</span> |
| <span id="809">809</span> |
| <span id="810">810</span> |
| <span id="811">811</span> |
| <span id="812">812</span> |
| <span id="813">813</span> |
| <span id="814">814</span> |
| </pre><pre class="rust"><code><span class="kw">use </span>core::mem::size_of; |
| <span class="kw">use </span>core::num::Wrapping; |
| <span class="kw">use </span>core::{f32, f64}; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">use </span>core::{i128, u128}; |
| <span class="kw">use </span>core::{i16, i32, i64, i8, isize}; |
| <span class="kw">use </span>core::{u16, u32, u64, u8, usize}; |
| |
| <span class="doccomment">/// A generic trait for converting a value to a number. |
| /// |
| /// A value can be represented by the target type when it lies within |
| /// the range of scalars supported by the target type. |
| /// For example, a negative integer cannot be represented by an unsigned |
| /// integer type, and an `i64` with a very high magnitude might not be |
| /// convertible to an `i32`. |
| /// On the other hand, conversions with possible precision loss or truncation |
| /// are admitted, like an `f32` with a decimal part to an integer type, or |
| /// even a large `f64` saturating to `f32` infinity. |
| </span><span class="kw">pub trait </span>ToPrimitive { |
| <span class="doccomment">/// Converts the value of `self` to an `isize`. If the value cannot be |
| /// represented by an `isize`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_isize(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><isize> { |
| <span class="self">self</span>.to_i64().as_ref().and_then(ToPrimitive::to_isize) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `i8`. If the value cannot be |
| /// represented by an `i8`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_i8(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i8> { |
| <span class="self">self</span>.to_i64().as_ref().and_then(ToPrimitive::to_i8) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `i16`. If the value cannot be |
| /// represented by an `i16`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_i16(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i16> { |
| <span class="self">self</span>.to_i64().as_ref().and_then(ToPrimitive::to_i16) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `i32`. If the value cannot be |
| /// represented by an `i32`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_i32(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i32> { |
| <span class="self">self</span>.to_i64().as_ref().and_then(ToPrimitive::to_i32) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `i64`. If the value cannot be |
| /// represented by an `i64`, then `None` is returned. |
| </span><span class="kw">fn </span>to_i64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i64>; |
| |
| <span class="doccomment">/// Converts the value of `self` to an `i128`. If the value cannot be |
| /// represented by an `i128` (`i64` under the default implementation), then |
| /// `None` is returned. |
| /// |
| /// This method is only available with feature `i128` enabled on Rust >= 1.26. |
| /// |
| /// The default implementation converts through `to_i64()`. Types implementing |
| /// this trait should override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| #[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_i128(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><i128> { |
| <span class="self">self</span>.to_i64().map(From::from) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to a `usize`. If the value cannot be |
| /// represented by a `usize`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_usize(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><usize> { |
| <span class="self">self</span>.to_u64().as_ref().and_then(ToPrimitive::to_usize) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to a `u8`. If the value cannot be |
| /// represented by a `u8`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_u8(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u8> { |
| <span class="self">self</span>.to_u64().as_ref().and_then(ToPrimitive::to_u8) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to a `u16`. If the value cannot be |
| /// represented by a `u16`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_u16(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u16> { |
| <span class="self">self</span>.to_u64().as_ref().and_then(ToPrimitive::to_u16) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to a `u32`. If the value cannot be |
| /// represented by a `u32`, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_u32(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u32> { |
| <span class="self">self</span>.to_u64().as_ref().and_then(ToPrimitive::to_u32) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to a `u64`. If the value cannot be |
| /// represented by a `u64`, then `None` is returned. |
| </span><span class="kw">fn </span>to_u64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u64>; |
| |
| <span class="doccomment">/// Converts the value of `self` to a `u128`. If the value cannot be |
| /// represented by a `u128` (`u64` under the default implementation), then |
| /// `None` is returned. |
| /// |
| /// This method is only available with feature `i128` enabled on Rust >= 1.26. |
| /// |
| /// The default implementation converts through `to_u64()`. Types implementing |
| /// this trait should override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| #[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_u128(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><u128> { |
| <span class="self">self</span>.to_u64().map(From::from) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `f32`. Overflows may map to positive |
| /// or negative inifinity, otherwise `None` is returned if the value cannot |
| /// be represented by an `f32`. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f32(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f32> { |
| <span class="self">self</span>.to_f64().as_ref().and_then(ToPrimitive::to_f32) |
| } |
| |
| <span class="doccomment">/// Converts the value of `self` to an `f64`. Overflows may map to positive |
| /// or negative inifinity, otherwise `None` is returned if the value cannot |
| /// be represented by an `f64`. |
| /// |
| /// The default implementation tries to convert through `to_i64()`, and |
| /// failing that through `to_u64()`. Types implementing this trait should |
| /// override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f64> { |
| <span class="kw">match </span><span class="self">self</span>.to_i64() { |
| <span class="prelude-val">Some</span>(i) => i.to_f64(), |
| <span class="prelude-val">None </span>=> <span class="self">self</span>.to_u64().as_ref().and_then(ToPrimitive::to_f64), |
| } |
| } |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_int_to_int { |
| (<span class="macro-nonterminal">$SrcT</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$DstT</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$DstT</span>> { |
| <span class="kw">let </span>min = <span class="macro-nonterminal">$DstT::MIN </span><span class="kw">as </span><span class="macro-nonterminal">$SrcT</span>; |
| <span class="kw">let </span>max = <span class="macro-nonterminal">$DstT::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$SrcT</span>; |
| <span class="kw">if </span>size_of::<<span class="macro-nonterminal">$SrcT</span>>() <= size_of::<<span class="macro-nonterminal">$DstT</span>>() || (min <= <span class="kw-2">*</span><span class="self">self </span>&& <span class="kw-2">*</span><span class="self">self </span><= max) { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$DstT</span>) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>} |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_int_to_uint { |
| (<span class="macro-nonterminal">$SrcT</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$DstT</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$DstT</span>> { |
| <span class="kw">let </span>max = <span class="macro-nonterminal">$DstT::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$SrcT</span>; |
| <span class="kw">if </span><span class="number">0 </span><= <span class="kw-2">*</span><span class="self">self </span>&& (size_of::<<span class="macro-nonterminal">$SrcT</span>>() <= size_of::<<span class="macro-nonterminal">$DstT</span>>() || <span class="kw-2">*</span><span class="self">self </span><= max) { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$DstT</span>) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>} |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_int { |
| (<span class="macro-nonterminal">$T</span>:ident) => { |
| <span class="kw">impl </span>ToPrimitive <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="macro">impl_to_primitive_int_to_int! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_isize -> isize; |
| <span class="kw">fn </span>to_i8 -> i8; |
| <span class="kw">fn </span>to_i16 -> i16; |
| <span class="kw">fn </span>to_i32 -> i32; |
| <span class="kw">fn </span>to_i64 -> i64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_i128 -> i128; |
| } |
| |
| <span class="macro">impl_to_primitive_int_to_uint! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_usize -> usize; |
| <span class="kw">fn </span>to_u8 -> u8; |
| <span class="kw">fn </span>to_u16 -> u16; |
| <span class="kw">fn </span>to_u32 -> u32; |
| <span class="kw">fn </span>to_u64 -> u64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_u128 -> u128; |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f32(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f32> { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span>f32) |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f64> { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span>f64) |
| } |
| } |
| }; |
| } |
| |
| <span class="macro">impl_to_primitive_int!</span>(isize); |
| <span class="macro">impl_to_primitive_int!</span>(i8); |
| <span class="macro">impl_to_primitive_int!</span>(i16); |
| <span class="macro">impl_to_primitive_int!</span>(i32); |
| <span class="macro">impl_to_primitive_int!</span>(i64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_to_primitive_int!</span>(i128); |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_uint_to_int { |
| (<span class="macro-nonterminal">$SrcT</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$DstT</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$DstT</span>> { |
| <span class="kw">let </span>max = <span class="macro-nonterminal">$DstT::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$SrcT</span>; |
| <span class="kw">if </span>size_of::<<span class="macro-nonterminal">$SrcT</span>>() < size_of::<<span class="macro-nonterminal">$DstT</span>>() || <span class="kw-2">*</span><span class="self">self </span><= max { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$DstT</span>) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>} |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_uint_to_uint { |
| (<span class="macro-nonterminal">$SrcT</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$DstT</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$DstT</span>> { |
| <span class="kw">let </span>max = <span class="macro-nonterminal">$DstT::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$SrcT</span>; |
| <span class="kw">if </span>size_of::<<span class="macro-nonterminal">$SrcT</span>>() <= size_of::<<span class="macro-nonterminal">$DstT</span>>() || <span class="kw-2">*</span><span class="self">self </span><= max { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$DstT</span>) |
| } <span class="kw">else </span>{ |
| <span class="prelude-val">None |
| </span>} |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_uint { |
| (<span class="macro-nonterminal">$T</span>:ident) => { |
| <span class="kw">impl </span>ToPrimitive <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="macro">impl_to_primitive_uint_to_int! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_isize -> isize; |
| <span class="kw">fn </span>to_i8 -> i8; |
| <span class="kw">fn </span>to_i16 -> i16; |
| <span class="kw">fn </span>to_i32 -> i32; |
| <span class="kw">fn </span>to_i64 -> i64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_i128 -> i128; |
| } |
| |
| <span class="macro">impl_to_primitive_uint_to_uint! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_usize -> usize; |
| <span class="kw">fn </span>to_u8 -> u8; |
| <span class="kw">fn </span>to_u16 -> u16; |
| <span class="kw">fn </span>to_u32 -> u32; |
| <span class="kw">fn </span>to_u64 -> u64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_u128 -> u128; |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f32(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f32> { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span>f32) |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>to_f64(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><f64> { |
| <span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span>f64) |
| } |
| } |
| }; |
| } |
| |
| <span class="macro">impl_to_primitive_uint!</span>(usize); |
| <span class="macro">impl_to_primitive_uint!</span>(u8); |
| <span class="macro">impl_to_primitive_uint!</span>(u16); |
| <span class="macro">impl_to_primitive_uint!</span>(u32); |
| <span class="macro">impl_to_primitive_uint!</span>(u64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_to_primitive_uint!</span>(u128); |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_float_to_float { |
| (<span class="macro-nonterminal">$SrcT</span>:ident : $( <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$DstT</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$DstT</span>> { |
| <span class="comment">// We can safely cast all values, whether NaN, +-inf, or finite. |
| // Finite values that are reducing size may saturate to +-inf. |
| </span><span class="prelude-val">Some</span>(<span class="kw-2">*</span><span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$DstT</span>) |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="attribute">#[cfg(has_to_int_unchecked)] |
| </span><span class="macro">macro_rules! </span>float_to_int_unchecked { |
| <span class="comment">// SAFETY: Must not be NaN or infinite; must be representable as the integer after truncating. |
| // We already checked that the float is in the exclusive range `(MIN-1, MAX+1)`. |
| </span>(<span class="macro-nonterminal">$float</span>:expr => <span class="macro-nonterminal">$int</span>:ty) => { |
| <span class="kw">unsafe </span>{ <span class="macro-nonterminal">$float</span>.to_int_unchecked::<<span class="macro-nonterminal">$int</span>>() } |
| }; |
| } |
| |
| <span class="attribute">#[cfg(not(has_to_int_unchecked))] |
| </span><span class="macro">macro_rules! </span>float_to_int_unchecked { |
| (<span class="macro-nonterminal">$float</span>:expr => <span class="macro-nonterminal">$int</span>:ty) => { |
| <span class="macro-nonterminal">$float </span><span class="kw">as </span><span class="macro-nonterminal">$int |
| </span>}; |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_float_to_signed_int { |
| (<span class="macro-nonterminal">$f</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$i</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$i</span>> { |
| <span class="comment">// Float as int truncates toward zero, so we want to allow values |
| // in the exclusive range `(MIN-1, MAX+1)`. |
| </span><span class="kw">if </span>size_of::<<span class="macro-nonterminal">$f</span>>() > size_of::<<span class="macro-nonterminal">$i</span>>() { |
| <span class="comment">// With a larger size, we can represent the range exactly. |
| </span><span class="kw">const </span>MIN_M1: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$i::MIN </span><span class="kw">as </span><span class="macro-nonterminal">$f </span>- <span class="number">1.0</span>; |
| <span class="kw">const </span>MAX_P1: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$i::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$f </span>+ <span class="number">1.0</span>; |
| <span class="kw">if </span><span class="kw-2">*</span><span class="self">self </span>> MIN_M1 && <span class="kw-2">*</span><span class="self">self </span>< MAX_P1 { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(<span class="macro">float_to_int_unchecked!</span>(<span class="kw-2">*</span><span class="self">self </span>=> <span class="macro-nonterminal">$i</span>)); |
| } |
| } <span class="kw">else </span>{ |
| <span class="comment">// We can't represent `MIN-1` exactly, but there's no fractional part |
| // at this magnitude, so we can just use a `MIN` inclusive boundary. |
| </span><span class="kw">const </span>MIN: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$i::MIN </span><span class="kw">as </span><span class="macro-nonterminal">$f</span>; |
| <span class="comment">// We can't represent `MAX` exactly, but it will round up to exactly |
| // `MAX+1` (a power of two) when we cast it. |
| </span><span class="kw">const </span>MAX_P1: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$i::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$f</span>; |
| <span class="kw">if </span><span class="kw-2">*</span><span class="self">self </span>>= MIN && <span class="kw-2">*</span><span class="self">self </span>< MAX_P1 { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(<span class="macro">float_to_int_unchecked!</span>(<span class="kw-2">*</span><span class="self">self </span>=> <span class="macro-nonterminal">$i</span>)); |
| } |
| } |
| <span class="prelude-val">None |
| </span>} |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_float_to_unsigned_int { |
| (<span class="macro-nonterminal">$f</span>:ident : $( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$u</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$u</span>> { |
| <span class="comment">// Float as int truncates toward zero, so we want to allow values |
| // in the exclusive range `(-1, MAX+1)`. |
| </span><span class="kw">if </span>size_of::<<span class="macro-nonterminal">$f</span>>() > size_of::<<span class="macro-nonterminal">$u</span>>() { |
| <span class="comment">// With a larger size, we can represent the range exactly. |
| </span><span class="kw">const </span>MAX_P1: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$u::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$f </span>+ <span class="number">1.0</span>; |
| <span class="kw">if </span><span class="kw-2">*</span><span class="self">self </span>> -<span class="number">1.0 </span>&& <span class="kw-2">*</span><span class="self">self </span>< MAX_P1 { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(<span class="macro">float_to_int_unchecked!</span>(<span class="kw-2">*</span><span class="self">self </span>=> <span class="macro-nonterminal">$u</span>)); |
| } |
| } <span class="kw">else </span>{ |
| <span class="comment">// We can't represent `MAX` exactly, but it will round up to exactly |
| // `MAX+1` (a power of two) when we cast it. |
| // (`u128::MAX as f32` is infinity, but this is still ok.) |
| </span><span class="kw">const </span>MAX_P1: <span class="macro-nonterminal">$f </span>= <span class="macro-nonterminal">$u::MAX </span><span class="kw">as </span><span class="macro-nonterminal">$f</span>; |
| <span class="kw">if </span><span class="kw-2">*</span><span class="self">self </span>> -<span class="number">1.0 </span>&& <span class="kw-2">*</span><span class="self">self </span>< MAX_P1 { |
| <span class="kw">return </span><span class="prelude-val">Some</span>(<span class="macro">float_to_int_unchecked!</span>(<span class="kw-2">*</span><span class="self">self </span>=> <span class="macro-nonterminal">$u</span>)); |
| } |
| } |
| <span class="prelude-val">None |
| </span>} |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_float { |
| (<span class="macro-nonterminal">$T</span>:ident) => { |
| <span class="kw">impl </span>ToPrimitive <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="macro">impl_to_primitive_float_to_signed_int! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_isize -> isize; |
| <span class="kw">fn </span>to_i8 -> i8; |
| <span class="kw">fn </span>to_i16 -> i16; |
| <span class="kw">fn </span>to_i32 -> i32; |
| <span class="kw">fn </span>to_i64 -> i64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_i128 -> i128; |
| } |
| |
| <span class="macro">impl_to_primitive_float_to_unsigned_int! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_usize -> usize; |
| <span class="kw">fn </span>to_u8 -> u8; |
| <span class="kw">fn </span>to_u16 -> u16; |
| <span class="kw">fn </span>to_u32 -> u32; |
| <span class="kw">fn </span>to_u64 -> u64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_u128 -> u128; |
| } |
| |
| <span class="macro">impl_to_primitive_float_to_float! </span>{ <span class="macro-nonterminal">$T</span>: |
| <span class="kw">fn </span>to_f32 -> f32; |
| <span class="kw">fn </span>to_f64 -> f64; |
| } |
| } |
| }; |
| } |
| |
| <span class="macro">impl_to_primitive_float!</span>(f32); |
| <span class="macro">impl_to_primitive_float!</span>(f64); |
| |
| <span class="doccomment">/// A generic trait for converting a number to a value. |
| /// |
| /// A value can be represented by the target type when it lies within |
| /// the range of scalars supported by the target type. |
| /// For example, a negative integer cannot be represented by an unsigned |
| /// integer type, and an `i64` with a very high magnitude might not be |
| /// convertible to an `i32`. |
| /// On the other hand, conversions with possible precision loss or truncation |
| /// are admitted, like an `f32` with a decimal part to an integer type, or |
| /// even a large `f64` saturating to `f32` infinity. |
| </span><span class="kw">pub trait </span>FromPrimitive: Sized { |
| <span class="doccomment">/// Converts an `isize` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_isize(n: isize) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| n.to_i64().and_then(FromPrimitive::from_i64) |
| } |
| |
| <span class="doccomment">/// Converts an `i8` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i8(n: i8) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_i64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `i16` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i16(n: i16) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_i64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `i32` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i32(n: i32) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_i64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `i64` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="kw">fn </span>from_i64(n: i64) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>>; |
| |
| <span class="doccomment">/// Converts an `i128` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| /// |
| /// This method is only available with feature `i128` enabled on Rust >= 1.26. |
| /// |
| /// The default implementation converts through `from_i64()`. Types implementing |
| /// this trait should override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| #[cfg(has_i128)] |
| </span><span class="kw">fn </span>from_i128(n: i128) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| n.to_i64().and_then(FromPrimitive::from_i64) |
| } |
| |
| <span class="doccomment">/// Converts a `usize` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_usize(n: usize) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| n.to_u64().and_then(FromPrimitive::from_u64) |
| } |
| |
| <span class="doccomment">/// Converts an `u8` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u8(n: u8) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_u64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `u16` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u16(n: u16) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_u64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `u32` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u32(n: u32) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_u64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts an `u64` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="kw">fn </span>from_u64(n: u64) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>>; |
| |
| <span class="doccomment">/// Converts an `u128` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| /// |
| /// This method is only available with feature `i128` enabled on Rust >= 1.26. |
| /// |
| /// The default implementation converts through `from_u64()`. Types implementing |
| /// this trait should override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| #[cfg(has_i128)] |
| </span><span class="kw">fn </span>from_u128(n: u128) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| n.to_u64().and_then(FromPrimitive::from_u64) |
| } |
| |
| <span class="doccomment">/// Converts a `f32` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_f32(n: f32) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| FromPrimitive::from_f64(From::from(n)) |
| } |
| |
| <span class="doccomment">/// Converts a `f64` to return an optional value of this type. If the |
| /// value cannot be represented by this type, then `None` is returned. |
| /// |
| /// The default implementation tries to convert through `from_i64()`, and |
| /// failing that through `from_u64()`. Types implementing this trait should |
| /// override this method if they can represent a greater range. |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_f64(n: f64) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| <span class="kw">match </span>n.to_i64() { |
| <span class="prelude-val">Some</span>(i) => FromPrimitive::from_i64(i), |
| <span class="prelude-val">None </span>=> n.to_u64().and_then(FromPrimitive::from_u64), |
| } |
| } |
| } |
| |
| <span class="macro">macro_rules! </span>impl_from_primitive { |
| (<span class="macro-nonterminal">$T</span>:ty, <span class="macro-nonterminal">$to_ty</span>:ident) => { |
| <span class="attribute">#[allow(deprecated)] |
| </span><span class="kw">impl </span>FromPrimitive <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_isize(n: isize) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i8(n: i8) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i16(n: i16) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i32(n: i32) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_i64(n: i64) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[cfg(has_i128)] |
| #[inline] |
| </span><span class="kw">fn </span>from_i128(n: i128) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_usize(n: usize) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u8(n: u8) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u16(n: u16) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u32(n: u32) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_u64(n: u64) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[cfg(has_i128)] |
| #[inline] |
| </span><span class="kw">fn </span>from_u128(n: u128) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_f32(n: f32) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>from_f64(n: f64) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| n.<span class="macro-nonterminal">$to_ty</span>() |
| } |
| } |
| }; |
| } |
| |
| <span class="macro">impl_from_primitive!</span>(isize, to_isize); |
| <span class="macro">impl_from_primitive!</span>(i8, to_i8); |
| <span class="macro">impl_from_primitive!</span>(i16, to_i16); |
| <span class="macro">impl_from_primitive!</span>(i32, to_i32); |
| <span class="macro">impl_from_primitive!</span>(i64, to_i64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_from_primitive!</span>(i128, to_i128); |
| <span class="macro">impl_from_primitive!</span>(usize, to_usize); |
| <span class="macro">impl_from_primitive!</span>(u8, to_u8); |
| <span class="macro">impl_from_primitive!</span>(u16, to_u16); |
| <span class="macro">impl_from_primitive!</span>(u32, to_u32); |
| <span class="macro">impl_from_primitive!</span>(u64, to_u64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_from_primitive!</span>(u128, to_u128); |
| <span class="macro">impl_from_primitive!</span>(f32, to_f32); |
| <span class="macro">impl_from_primitive!</span>(f64, to_f64); |
| |
| <span class="macro">macro_rules! </span>impl_to_primitive_wrapping { |
| ($( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident -> <span class="macro-nonterminal">$i</span>:ident ; )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$i</span>> { |
| (<span class="self">self</span>.<span class="number">0</span>).<span class="macro-nonterminal">$method</span>() |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="kw">impl</span><T: ToPrimitive> ToPrimitive <span class="kw">for </span>Wrapping<T> { |
| <span class="macro">impl_to_primitive_wrapping! </span>{ |
| <span class="kw">fn </span>to_isize -> isize; |
| <span class="kw">fn </span>to_i8 -> i8; |
| <span class="kw">fn </span>to_i16 -> i16; |
| <span class="kw">fn </span>to_i32 -> i32; |
| <span class="kw">fn </span>to_i64 -> i64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_i128 -> i128; |
| |
| <span class="kw">fn </span>to_usize -> usize; |
| <span class="kw">fn </span>to_u8 -> u8; |
| <span class="kw">fn </span>to_u16 -> u16; |
| <span class="kw">fn </span>to_u32 -> u32; |
| <span class="kw">fn </span>to_u64 -> u64; |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>to_u128 -> u128; |
| |
| <span class="kw">fn </span>to_f32 -> f32; |
| <span class="kw">fn </span>to_f64 -> f64; |
| } |
| } |
| |
| <span class="macro">macro_rules! </span>impl_from_primitive_wrapping { |
| ($( $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">fn </span><span class="macro-nonterminal">$method</span>:ident ( <span class="macro-nonterminal">$i</span>:ident ); )<span class="kw-2">*</span>) => {$( |
| <span class="attribute">#[inline] |
| </span>$(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">fn </span><span class="macro-nonterminal">$method</span>(n: <span class="macro-nonterminal">$i</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| T::<span class="macro-nonterminal">$method</span>(n).map(Wrapping) |
| } |
| )<span class="kw-2">*</span>} |
| } |
| |
| <span class="kw">impl</span><T: FromPrimitive> FromPrimitive <span class="kw">for </span>Wrapping<T> { |
| <span class="macro">impl_from_primitive_wrapping! </span>{ |
| <span class="kw">fn </span>from_isize(isize); |
| <span class="kw">fn </span>from_i8(i8); |
| <span class="kw">fn </span>from_i16(i16); |
| <span class="kw">fn </span>from_i32(i32); |
| <span class="kw">fn </span>from_i64(i64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>from_i128(i128); |
| |
| <span class="kw">fn </span>from_usize(usize); |
| <span class="kw">fn </span>from_u8(u8); |
| <span class="kw">fn </span>from_u16(u16); |
| <span class="kw">fn </span>from_u32(u32); |
| <span class="kw">fn </span>from_u64(u64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="kw">fn </span>from_u128(u128); |
| |
| <span class="kw">fn </span>from_f32(f32); |
| <span class="kw">fn </span>from_f64(f64); |
| } |
| } |
| |
| <span class="doccomment">/// Cast from one machine scalar to another. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # use num_traits as num; |
| /// let twenty: f32 = num::cast(0x14).unwrap(); |
| /// assert_eq!(twenty, 20f32); |
| /// ``` |
| /// |
| </span><span class="attribute">#[inline] |
| </span><span class="kw">pub fn </span>cast<T: NumCast, U: NumCast>(n: T) -> <span class="prelude-ty">Option</span><U> { |
| NumCast::from(n) |
| } |
| |
| <span class="doccomment">/// An interface for casting between machine scalars. |
| </span><span class="kw">pub trait </span>NumCast: Sized + ToPrimitive { |
| <span class="doccomment">/// Creates a number from another value that can be converted into |
| /// a primitive via the `ToPrimitive` trait. If the source value cannot be |
| /// represented by the target type, then `None` is returned. |
| /// |
| /// A value can be represented by the target type when it lies within |
| /// the range of scalars supported by the target type. |
| /// For example, a negative integer cannot be represented by an unsigned |
| /// integer type, and an `i64` with a very high magnitude might not be |
| /// convertible to an `i32`. |
| /// On the other hand, conversions with possible precision loss or truncation |
| /// are admitted, like an `f32` with a decimal part to an integer type, or |
| /// even a large `f64` saturating to `f32` infinity. |
| </span><span class="kw">fn </span>from<T: ToPrimitive>(n: T) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>>; |
| } |
| |
| <span class="macro">macro_rules! </span>impl_num_cast { |
| (<span class="macro-nonterminal">$T</span>:ty, <span class="macro-nonterminal">$conv</span>:ident) => { |
| <span class="kw">impl </span>NumCast <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="attribute">#[inline] |
| #[allow(deprecated)] |
| </span><span class="kw">fn </span>from<N: ToPrimitive>(n: N) -> <span class="prelude-ty">Option</span><<span class="macro-nonterminal">$T</span>> { |
| <span class="comment">// `$conv` could be generated using `concat_idents!`, but that |
| // macro seems to be broken at the moment |
| </span>n.<span class="macro-nonterminal">$conv</span>() |
| } |
| } |
| }; |
| } |
| |
| <span class="macro">impl_num_cast!</span>(u8, to_u8); |
| <span class="macro">impl_num_cast!</span>(u16, to_u16); |
| <span class="macro">impl_num_cast!</span>(u32, to_u32); |
| <span class="macro">impl_num_cast!</span>(u64, to_u64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_num_cast!</span>(u128, to_u128); |
| <span class="macro">impl_num_cast!</span>(usize, to_usize); |
| <span class="macro">impl_num_cast!</span>(i8, to_i8); |
| <span class="macro">impl_num_cast!</span>(i16, to_i16); |
| <span class="macro">impl_num_cast!</span>(i32, to_i32); |
| <span class="macro">impl_num_cast!</span>(i64, to_i64); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_num_cast!</span>(i128, to_i128); |
| <span class="macro">impl_num_cast!</span>(isize, to_isize); |
| <span class="macro">impl_num_cast!</span>(f32, to_f32); |
| <span class="macro">impl_num_cast!</span>(f64, to_f64); |
| |
| <span class="kw">impl</span><T: NumCast> NumCast <span class="kw">for </span>Wrapping<T> { |
| <span class="kw">fn </span>from<U: ToPrimitive>(n: U) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| T::from(n).map(Wrapping) |
| } |
| } |
| |
| <span class="doccomment">/// A generic interface for casting between machine scalars with the |
| /// `as` operator, which admits narrowing and precision loss. |
| /// Implementers of this trait `AsPrimitive` should behave like a primitive |
| /// numeric type (e.g. a newtype around another primitive), and the |
| /// intended conversion must never fail. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// # use num_traits::AsPrimitive; |
| /// let three: i32 = (3.14159265f32).as_(); |
| /// assert_eq!(three, 3); |
| /// ``` |
| /// |
| /// # Safety |
| /// |
| /// **In Rust versions before 1.45.0**, some uses of the `as` operator were not entirely safe. |
| /// In particular, it was undefined behavior if |
| /// a truncated floating point value could not fit in the target integer |
| /// type ([#10184](https://github.com/rust-lang/rust/issues/10184)). |
| /// |
| /// ```ignore |
| /// # use num_traits::AsPrimitive; |
| /// let x: u8 = (1.04E+17).as_(); // UB |
| /// ``` |
| /// |
| </span><span class="kw">pub trait </span>AsPrimitive<T>: <span class="lifetime">'static </span>+ Copy |
| <span class="kw">where |
| </span>T: <span class="lifetime">'static </span>+ Copy, |
| { |
| <span class="doccomment">/// Convert a value to another, using the `as` operator. |
| </span><span class="kw">fn </span>as_(<span class="self">self</span>) -> T; |
| } |
| |
| <span class="macro">macro_rules! </span>impl_as_primitive { |
| (@ <span class="macro-nonterminal">$T</span>: ty => $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>:meta]</span>)* <span class="kw">impl </span><span class="macro-nonterminal">$U</span>: ty ) => { |
| $(<span class="attribute">#[<span class="macro-nonterminal">$cfg</span>]</span>)* |
| <span class="kw">impl </span>AsPrimitive<<span class="macro-nonterminal">$U</span>> <span class="kw">for </span><span class="macro-nonterminal">$T </span>{ |
| <span class="attribute">#[inline] </span><span class="kw">fn </span>as_(<span class="self">self</span>) -> <span class="macro-nonterminal">$U </span>{ <span class="self">self </span><span class="kw">as </span><span class="macro-nonterminal">$U </span>} |
| } |
| }; |
| (@ <span class="macro-nonterminal">$T</span>: ty => { $( <span class="macro-nonterminal">$U</span>: ty ),* } ) => {$( |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> <span class="kw">impl </span><span class="macro-nonterminal">$U</span>); |
| )<span class="kw-2">*</span>}; |
| (<span class="macro-nonterminal">$T</span>: ty => { $( <span class="macro-nonterminal">$U</span>: ty ),* } ) => { |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> { $( <span class="macro-nonterminal">$U </span>),* }); |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> { u8, u16, u32, u64, usize }); |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> <span class="attribute">#[cfg(has_i128)] </span><span class="kw">impl </span>u128); |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> { i8, i16, i32, i64, isize }); |
| <span class="macro">impl_as_primitive!</span>(@ <span class="macro-nonterminal">$T </span>=> <span class="attribute">#[cfg(has_i128)] </span><span class="kw">impl </span>i128); |
| }; |
| } |
| |
| <span class="macro">impl_as_primitive!</span>(u8 => { char, f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(i8 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(u16 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(i16 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(u32 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(i32 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(u64 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(i64 => { f32, f64 }); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_as_primitive!</span>(u128 => { f32, f64 }); |
| <span class="attribute">#[cfg(has_i128)] |
| </span><span class="macro">impl_as_primitive!</span>(i128 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(usize => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(isize => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(f32 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(f64 => { f32, f64 }); |
| <span class="macro">impl_as_primitive!</span>(char => { char }); |
| <span class="macro">impl_as_primitive!</span>(bool => {}); |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="num_traits" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |