| // Copyright 2008 and onwards Google, Inc. |
| // |
| // #status: RECOMMENDED |
| // #category: operations on strings |
| // #summary: Merges strings or numbers with no delimiter. |
| // |
| #ifndef STRINGS_STRCAT_H_ |
| #define STRINGS_STRCAT_H_ |
| |
| #include <string> |
| using std::string; |
| |
| #include "gutil/integral_types.h" |
| #include "gutil/strings/numbers.h" |
| #include "gutil/strings/stringpiece.h" |
| |
| // The AlphaNum type was designed to be used as the parameter type for StrCat(). |
| // I suppose that any routine accepting either a string or a number could accept |
| // it. The basic idea is that by accepting a "const AlphaNum &" as an argument |
| // to your function, your callers will automagically convert bools, integers, |
| // and floating point values to strings for you. |
| // |
| // Conversion from 8-bit values is not accepted because if it were, then an |
| // attempt to pass ':' instead of ":" might result in a 58 ending up in your |
| // result. |
| // |
| // Bools convert to "0" or "1". |
| // |
| // Floating point values are converted to a string which, if passed to strtod(), |
| // would produce the exact same original double (except in case of NaN; all NaNs |
| // are considered the same value). We try to keep the string short but it's not |
| // guaranteed to be as short as possible. |
| // |
| // This class has implicit constructors. |
| // Style guide exception granted: |
| // http://goto/style-guide-exception-20978288 |
| // |
| struct AlphaNum { |
| StringPiece piece; |
| char digits[kFastToBufferSize]; |
| |
| // No bool ctor -- bools convert to an integral type. |
| // A bool ctor would also convert incoming pointers (bletch). |
| |
| AlphaNum(int32 i32) // NOLINT(runtime/explicit) |
| : piece(digits, FastInt32ToBufferLeft(i32, digits) - &digits[0]) {} |
| AlphaNum(uint32 u32) // NOLINT(runtime/explicit) |
| : piece(digits, FastUInt32ToBufferLeft(u32, digits) - &digits[0]) {} |
| AlphaNum(int64 i64) // NOLINT(runtime/explicit) |
| : piece(digits, FastInt64ToBufferLeft(i64, digits) - &digits[0]) {} |
| AlphaNum(uint64 u64) // NOLINT(runtime/explicit) |
| : piece(digits, FastUInt64ToBufferLeft(u64, digits) - &digits[0]) {} |
| |
| #if defined(__APPLE__) |
| AlphaNum(size_t size) // NOLINT(runtime/explicit) |
| : piece(digits, FastUInt64ToBufferLeft(size, digits) - &digits[0]) {} |
| #endif |
| |
| AlphaNum(float f) // NOLINT(runtime/explicit) |
| : piece(digits, strlen(FloatToBuffer(f, digits))) {} |
| AlphaNum(double f) // NOLINT(runtime/explicit) |
| : piece(digits, strlen(DoubleToBuffer(f, digits))) {} |
| |
| AlphaNum(const char *c_str) : piece(c_str) {} // NOLINT(runtime/explicit) |
| AlphaNum(StringPiece pc) |
| : piece(std::move(pc)) {} // NOLINT(runtime/explicit) |
| AlphaNum(const string &s) : piece(s) {} // NOLINT(runtime/explicit) |
| |
| StringPiece::size_type size() const { return piece.size(); } |
| const char *data() const { return piece.data(); } |
| |
| private: |
| // Use ":" not ':' |
| AlphaNum(char c); // NOLINT(runtime/explicit) |
| }; |
| |
| extern AlphaNum gEmptyAlphaNum; |
| |
| // ---------------------------------------------------------------------- |
| // StrCat() |
| // This merges the given strings or numbers, with no delimiter. This |
| // is designed to be the fastest possible way to construct a string out |
| // of a mix of raw C strings, StringPieces, strings, bool values, |
| // and numeric values. |
| // |
| // Don't use this for user-visible strings. The localization process |
| // works poorly on strings built up out of fragments. |
| // |
| // For clarity and performance, don't use StrCat when appending to a |
| // string. In particular, avoid using any of these (anti-)patterns: |
| // str.append(StrCat(...) |
| // str += StrCat(...) |
| // str = StrCat(str, ...) |
| // where the last is the worse, with the potential to change a loop |
| // from a linear time operation with O(1) dynamic allocations into a |
| // quadratic time operation with O(n) dynamic allocations. StrAppend |
| // is a better choice than any of the above, subject to the restriction |
| // of StrAppend(&str, a, b, c, ...) that none of the a, b, c, ... may |
| // be a reference into str. |
| // ---------------------------------------------------------------------- |
| |
| string StrCat(const AlphaNum &a); |
| string StrCat(const AlphaNum &a, const AlphaNum &b); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g); |
| string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h); |
| |
| namespace strings { |
| namespace internal { |
| |
| // Do not call directly - this is not part of the public API. |
| string StrCatNineOrMore(const AlphaNum *a1, ...); |
| |
| } // namespace internal |
| } // namespace strings |
| |
| // Support 9 or more arguments |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u, |
| const AlphaNum &v) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, &v, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u, |
| const AlphaNum &v, const AlphaNum &w) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, &v, &w, null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u, |
| const AlphaNum &v, const AlphaNum &w, const AlphaNum &x) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, &v, &w, &x, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u, |
| const AlphaNum &v, const AlphaNum &w, const AlphaNum &x, |
| const AlphaNum &y) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, &v, &w, &x, &y, |
| null_alphanum); |
| } |
| |
| inline string StrCat(const AlphaNum &a, const AlphaNum &b, const AlphaNum &c, |
| const AlphaNum &d, const AlphaNum &e, const AlphaNum &f, |
| const AlphaNum &g, const AlphaNum &h, const AlphaNum &i, |
| const AlphaNum &j, const AlphaNum &k, const AlphaNum &l, |
| const AlphaNum &m, const AlphaNum &n, const AlphaNum &o, |
| const AlphaNum &p, const AlphaNum &q, const AlphaNum &r, |
| const AlphaNum &s, const AlphaNum &t, const AlphaNum &u, |
| const AlphaNum &v, const AlphaNum &w, const AlphaNum &x, |
| const AlphaNum &y, const AlphaNum &z) { |
| const AlphaNum* null_alphanum = NULL; |
| return strings::internal::StrCatNineOrMore(&a, &b, &c, &d, &e, &f, &g, &h, &i, |
| &j, &k, &l, &m, &n, &o, &p, &q, &r, |
| &s, &t, &u, &v, &w, &x, &y, &z, |
| null_alphanum); |
| } |
| |
| // ---------------------------------------------------------------------- |
| // StrAppend() |
| // Same as above, but adds the output to the given string. |
| // WARNING: For speed, StrAppend does not try to check each of its input |
| // arguments to be sure that they are not a subset of the string being |
| // appended to. That is, while this will work: |
| // |
| // string s = "foo"; |
| // s += s; |
| // |
| // This will not (necessarily) work: |
| // |
| // string s = "foo"; |
| // StrAppend(&s, s); |
| // |
| // Note: while StrCat supports appending up to 12 arguments, StrAppend |
| // is currently limited to 9. That's rarely an issue except when |
| // automatically transforming StrCat to StrAppend, and can easily be |
| // worked around as consecutive calls to StrAppend are quite efficient. |
| // ---------------------------------------------------------------------- |
| |
| void StrAppend(string *dest, const AlphaNum &a); |
| void StrAppend(string *dest, const AlphaNum &a, const AlphaNum &b); |
| void StrAppend(string *dest, const AlphaNum &a, const AlphaNum &b, |
| const AlphaNum &c); |
| void StrAppend(string *dest, const AlphaNum &a, const AlphaNum &b, |
| const AlphaNum &c, const AlphaNum &d); |
| |
| // Support up to 9 params by using a default empty AlphaNum. |
| void StrAppend(string *dest, const AlphaNum &a, const AlphaNum &b, |
| const AlphaNum &c, const AlphaNum &d, const AlphaNum &e, |
| const AlphaNum &f = gEmptyAlphaNum, |
| const AlphaNum &g = gEmptyAlphaNum, |
| const AlphaNum &h = gEmptyAlphaNum, |
| const AlphaNum &i = gEmptyAlphaNum); |
| |
| #endif // STRINGS_STRCAT_H_ |
