lib/d/src/thrift/internal/codegen.d - thrift - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements. See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership. The ASF licenses this file
  * to you under the Apache License, Version 2.0 (the
  * "License"); you may not use this file except in compliance
  * with the License. You may obtain a copy of the License at
  *
  *   http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing,
  * software distributed under the License is distributed on an
  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  * KIND, either express or implied. See the License for the
  * specific language governing permissions and limitations
  * under the License.
  */

 module thrift.internal.codegen;

 import std.algorithm : canFind;
 import std.traits : InterfacesTuple, isSomeFunction, isSomeString;
 import std.typetuple : staticIndexOf, staticMap, NoDuplicates, TypeTuple;
 import thrift.codegen.base;

 /**
  * Removes all type qualifiers from T.
  *
  * In contrast to std.traits.Unqual, FullyUnqual also removes qualifiers from
  * array elements (e.g. immutable(byte[]) -> byte[], not immutable(byte)[]),
  * excluding strings (string isn't reduced to char[]).
  */
 template FullyUnqual(T) {
   static if (is(T _ == const(U), U)) {
     alias FullyUnqual!U FullyUnqual;
   } else static if (is(T _ == immutable(U), U)) {
     alias FullyUnqual!U FullyUnqual;
   } else static if (is(T _ == shared(U), U)) {
     alias FullyUnqual!U FullyUnqual;
   } else static if (is(T _ == U[], U) && !isSomeString!T) {
     alias FullyUnqual!(U)[] FullyUnqual;
   } else static if (is(T _ == V[K], K, V)) {
     alias FullyUnqual!(V)[FullyUnqual!K] FullyUnqual;
   } else {
     alias T FullyUnqual;
   }
 }

 /**
  * true if null can be assigned to the passed type, false if not.
  */
 template isNullable(T) {
   enum isNullable = __traits(compiles, { T t = null; });
 }

 template isStruct(T) {
   enum isStruct = is(T == struct);
 }

 template isException(T) {
  enum isException = is(T : Exception);
 }

 template isEnum(T) {
   enum isEnum = is(T == enum);
 }

 /**
  * Aliases itself to T.name.
  */
 template GetMember(T, string name) {
   mixin("alias T." ~ name ~ " GetMember;");
 }

 /**
  * Aliases itself to typeof(symbol).
  */
 template TypeOf(alias symbol) {
   alias typeof(symbol) TypeOf;
 }

 /**
  * Aliases itself to the type of the T member called name.
  */
 alias Compose!(TypeOf, GetMember) MemberType;

 /**
  * Returns the field metadata array for T if any, or an empty array otherwise.
  */
 template getFieldMeta(T) if (isStruct!T || isException!T) {
   static if (is(typeof(T.fieldMeta) == TFieldMeta[])) {
     enum getFieldMeta = T.fieldMeta;
   } else {
     enum TFieldMeta[] getFieldMeta = [];
   }
 }

 /**
  * Merges the field metadata array for D with the passed array.
  */
 template mergeFieldMeta(T, alias fieldMetaData = cast(TFieldMeta[])null) {
   // Note: We don't use getFieldMeta here to avoid bug if it is instantiated
   // from TIsSetFlags, see comment there.
   static if (is(typeof(T.fieldMeta) == TFieldMeta[])) {
     enum mergeFieldMeta = T.fieldMeta ~ fieldMetaData;
   } else {
     enum TFieldMeta[] mergeFieldMeta = fieldMetaData;
   }
 }

 /**
  * Returns the field requirement level for T.name.
  */
 template memberReq(T, string name, alias fieldMetaData = cast(TFieldMeta[])null) {
   enum memberReq = memberReqImpl!(T, name, fieldMetaData).result;
 }

 private {
   import std.algorithm : find;
   // DMD @@BUG@@: Missing import leads to failing build without error
   // message in unittest/debug/thrift/codegen/async_client.
   import std.array : empty, front;

   template memberReqImpl(T, string name, alias fieldMetaData) {
     enum meta = find!`a.name == b`(mergeFieldMeta!(T, fieldMetaData), name);
     static if (meta.empty || meta.front.req == TReq.AUTO) {
       static if (isNullable!(MemberType!(T, name))) {
         enum result = TReq.OPTIONAL;
       } else {
         enum result = TReq.REQUIRED;
       }
     } else {
       enum result = meta.front.req;
     }
   }
 }


 template notIgnored(T, string name, alias fieldMetaData = cast(TFieldMeta[])null) {
   enum notIgnored = memberReq!(T, name, fieldMetaData) != TReq.IGNORE;
 }

 /**
  * Returns the method metadata array for T if any, or an empty array otherwise.
  */
 template getMethodMeta(T) if (isService!T) {
   static if (is(typeof(T.methodMeta) == TMethodMeta[])) {
     enum getMethodMeta = T.methodMeta;
   } else {
     enum TMethodMeta[] getMethodMeta = [];
   }
 }


 /**
  * true if T.name is a member variable. Exceptions include methods, static
  * members, artifacts like package aliases, …
  */
 template isValueMember(T, string name) {
   static if (!is(MemberType!(T, name))) {
     enum isValueMember = false;
   } else static if (
     is(MemberType!(T, name) == void) ||
     isSomeFunction!(MemberType!(T, name)) ||
     __traits(compiles, { return mixin("T." ~ name); }())
   ) {
     enum isValueMember = false;
   } else {
     enum isValueMember = true;
   }
 }

 /**
  * Returns a tuple containing the names of the fields of T, not including
  * inherited fields. If a member is marked as TReq.IGNORE, it is not included
  * as well.
  */
 template FieldNames(T, alias fieldMetaData = cast(TFieldMeta[])null) {
   alias StaticFilter!(
     All!(
       doesNotReadMembers,
       PApply!(isValueMember, T),
       PApply!(notIgnored, T, PApplySkip, fieldMetaData)
     ),
     __traits(derivedMembers, T)
   ) FieldNames;
 }

 /*
  * true if the passed member name is not a method generated by the
  * TStructHelpers template that in its implementations queries the struct
  * members.
  *
  * Kludge used internally to break a cycle caused a DMD forward reference
  * regression, see THRIFT-2130.
  */
 enum doesNotReadMembers(string name) = !["opEquals", "thriftOpEqualsImpl",
   "toString", "thriftToStringImpl"].canFind(name);

 template derivedMembers(T) {
   alias TypeTuple!(__traits(derivedMembers, T)) derivedMembers;
 }

 template AllMemberMethodNames(T) if (isService!T) {
   alias NoDuplicates!(
     FilterMethodNames!(
       T,
       staticMap!(
         derivedMembers,
         TypeTuple!(T, InterfacesTuple!T)
       )
     )
   ) AllMemberMethodNames;
 }

 template FilterMethodNames(T, MemberNames...) {
   alias StaticFilter!(
     CompilesAndTrue!(
       Compose!(isSomeFunction, TypeOf, PApply!(GetMember, T))
     ),
     MemberNames
   ) FilterMethodNames;
 }

 /**
  * Returns a type tuple containing only the elements of T for which the
  * eponymous template predicate pred is true.
  *
  * Example:
  * ---
  * alias StaticFilter!(isIntegral, int, string, long, float[]) Filtered;
  * static assert(is(Filtered == TypeTuple!(int, long)));
  * ---
  */
 template StaticFilter(alias pred, T...) {
   static if (T.length == 0) {
     alias TypeTuple!() StaticFilter;
   } else static if (pred!(T[0])) {
     alias TypeTuple!(T[0], StaticFilter!(pred, T[1 .. $])) StaticFilter;
   } else {
     alias StaticFilter!(pred, T[1 .. $]) StaticFilter;
   }
 }

 /**
  * Binds the first n arguments of a template to a particular value (where n is
  * the number of arguments passed to PApply).
  *
  * The passed arguments are always applied starting from the left. However,
  * the special PApplySkip marker template can be used to indicate that an
  * argument should be skipped, so that e.g. the first and third argument
  * to a template can be fixed, but the second and remaining arguments would
  * still be left undefined.
  *
  * Skipping a number of parameters, but not providing enough arguments to
  * assign all of them during instantiation of the resulting template is an
  * error.
  *
  * Example:
  * ---
  * struct Foo(T, U, V) {}
  * alias PApply!(Foo, int, long) PartialFoo;
  * static assert(is(PartialFoo!float == Foo!(int, long, float)));
  *
  * alias PApply!(Test, int, PApplySkip, float) SkippedTest;
  * static assert(is(SkippedTest!long == Test!(int, long, float)));
  * ---
  */
 template PApply(alias Target, T...) {
   template PApply(U...) {
     alias Target!(PApplyMergeArgs!(ConfinedTuple!T, U).Result) PApply;
   }
 }

 /// Ditto.
 template PApplySkip() {}

 private template PApplyMergeArgs(alias Preset, Args...) {
   static if (Preset.length == 0) {
     alias Args Result;
   } else {
     enum nextSkip = staticIndexOf!(PApplySkip, Preset.Tuple);
     static if (nextSkip == -1) {
       alias TypeTuple!(Preset.Tuple, Args) Result;
     } else static if (Args.length == 0) {
       // Have to use a static if clause instead of putting the condition
       // directly into the assert to avoid DMD trying to access Args[0]
       // nevertheless below.
       static assert(false,
         "PArgsSkip encountered, but no argument left to bind.");
     } else {
       alias TypeTuple!(
         Preset.Tuple[0 .. nextSkip],
         Args[0],
         PApplyMergeArgs!(
           ConfinedTuple!(Preset.Tuple[nextSkip + 1 .. $]),
           Args[1 .. $]
         ).Result
       ) Result;
     }
   }
 }

 unittest {
   struct Test(T, U, V) {}
   alias PApply!(Test, int, long) PartialTest;
   static assert(is(PartialTest!float == Test!(int, long, float)));

   alias PApply!(Test, int, PApplySkip, float) SkippedTest;
   static assert(is(SkippedTest!long == Test!(int, long, float)));

   alias PApply!(Test, int, PApplySkip, PApplySkip) TwoSkipped;
   static assert(!__traits(compiles, TwoSkipped!long));
 }


 /**
  * Composes a number of templates. The result is a template equivalent to
  * all the passed templates evaluated from right to left, akin to the
  * mathematical function composition notation: Instantiating Compose!(A, B, C)
  * is the same as instantiating A!(B!(C!(…))).
  *
  * This is especially useful for creating a template to use with staticMap/
  * StaticFilter, as demonstrated below.
  *
  * Example:
  * ---
  * template AllMethodNames(T) {
  *   alias StaticFilter!(
  *     CompilesAndTrue!(
  *       Compose!(isSomeFunction, TypeOf, PApply!(GetMember, T))
  *     ),
  *     __traits(allMembers, T)
  *   ) AllMethodNames;
  * }
  *
  * pragma(msg, AllMethodNames!Object);
  * ---
  */
 template Compose(T...) {
   static if (T.length == 0) {
     template Compose(U...) {
       alias U Compose;
     }
   } else {
     template Compose(U...) {
       alias Instantiate!(T[0], Instantiate!(.Compose!(T[1 .. $]), U)) Compose;
     }
   }
 }

 /**
  * Instantiates the given template with the given list of parameters.
  *
  * Used to work around syntactic limiations of D with regard to instantiating
  * a template from a type tuple (e.g. T[0]!(...) is not valid) or a template
  * returning another template (e.g. Foo!(Bar)!(Baz) is not allowed).
  */
 template Instantiate(alias Template, Params...) {
   alias Template!Params Instantiate;
 }

 /**
  * Combines several template predicates using logical AND, i.e. instantiating
  * All!(a, b, c) with parameters P for some templates a, b, c is equivalent to
  * a!P && b!P && c!P.
  *
  * The templates are evaluated from left to right, aborting evaluation in a
  * shurt-cut manner if a false result is encountered, in which case the latter
  * instantiations do not need to compile.
  */
 template All(T...) {
   static if (T.length == 0) {
     template All(U...) {
       enum All = true;
     }
   } else {
     template All(U...) {
       static if (Instantiate!(T[0], U)) {
         alias Instantiate!(.All!(T[1 .. $]), U) All;
       } else {
         enum All = false;
       }
     }
   }
 }

 /**
  * Combines several template predicates using logical OR, i.e. instantiating
  * Any!(a, b, c) with parameters P for some templates a, b, c is equivalent to
  * a!P || b!P || c!P.
  *
  * The templates are evaluated from left to right, aborting evaluation in a
  * shurt-cut manner if a true result is encountered, in which case the latter
  * instantiations do not need to compile.
  */
 template Any(T...) {
   static if (T.length == 0) {
     template Any(U...) {
       enum Any = false;
     }
   } else {
     template Any(U...) {
       static if (Instantiate!(T[0], U)) {
         enum Any = true;
       } else {
         alias Instantiate!(.Any!(T[1 .. $]), U) Any;
       }
     }
   }
 }

 template ConfinedTuple(T...) {
   alias T Tuple;
   enum length = T.length;
 }

 /*
  * foreach (Item; Items) {
  *   List = Operator!(Item, List);
  * }
  * where Items is a ConfinedTuple and List is a type tuple.
  */
 template ForAllWithList(alias Items, alias Operator, List...) if (
   is(typeof(Items.length) : size_t)
 ){
   static if (Items.length == 0) {
     alias List ForAllWithList;
   } else {
     alias .ForAllWithList!(
       ConfinedTuple!(Items.Tuple[1 .. $]),
       Operator,
       Operator!(Items.Tuple[0], List)
     ) ForAllWithList;
   }
 }

 /**
  * Wraps the passed template predicate so it returns true if it compiles and
  * evaluates to true, false it it doesn't compile or evaluates to false.
  */
 template CompilesAndTrue(alias T) {
   template CompilesAndTrue(U...) {
     static if (is(typeof(T!U) : bool)) {
       enum bool CompilesAndTrue = T!U;
     } else {
       enum bool CompilesAndTrue = false;
     }
   }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you under the Apache License, Version 2.0 (the
	* "License"); you may not use this file except in compliance
	* with the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing,
	* software distributed under the License is distributed on an
	* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
	* KIND, either express or implied. See the License for the
	* specific language governing permissions and limitations
	* under the License.
	*/

	module thrift.internal.codegen;

	import std.algorithm : canFind;
	import std.traits : InterfacesTuple, isSomeFunction, isSomeString;
	import std.typetuple : staticIndexOf, staticMap, NoDuplicates, TypeTuple;
	import thrift.codegen.base;

	/**
	* Removes all type qualifiers from T.
	*
	* In contrast to std.traits.Unqual, FullyUnqual also removes qualifiers from
	* array elements (e.g. immutable(byte[]) -> byte[], not immutable(byte)[]),
	* excluding strings (string isn't reduced to char[]).
	*/
	template FullyUnqual(T) {
	static if (is(T _ == const(U), U)) {
	alias FullyUnqual!U FullyUnqual;
	} else static if (is(T _ == immutable(U), U)) {
	alias FullyUnqual!U FullyUnqual;
	} else static if (is(T _ == shared(U), U)) {
	alias FullyUnqual!U FullyUnqual;
	} else static if (is(T _ == U[], U) && !isSomeString!T) {
	alias FullyUnqual!(U)[] FullyUnqual;
	} else static if (is(T _ == V[K], K, V)) {
	alias FullyUnqual!(V)[FullyUnqual!K] FullyUnqual;
	} else {
	alias T FullyUnqual;
	}
	}

	/**
	* true if null can be assigned to the passed type, false if not.
	*/
	template isNullable(T) {
	enum isNullable = __traits(compiles, { T t = null; });
	}

	template isStruct(T) {
	enum isStruct = is(T == struct);
	}

	template isException(T) {
	enum isException = is(T : Exception);
	}

	template isEnum(T) {
	enum isEnum = is(T == enum);
	}

	/**
	* Aliases itself to T.name.
	*/
	template GetMember(T, string name) {
	mixin("alias T." ~ name ~ " GetMember;");
	}

	/**
	* Aliases itself to typeof(symbol).
	*/
	template TypeOf(alias symbol) {
	alias typeof(symbol) TypeOf;
	}

	/**
	* Aliases itself to the type of the T member called name.
	*/
	alias Compose!(TypeOf, GetMember) MemberType;

	/**
	* Returns the field metadata array for T if any, or an empty array otherwise.
	*/
	template getFieldMeta(T) if (isStruct!T \|\| isException!T) {
	static if (is(typeof(T.fieldMeta) == TFieldMeta[])) {
	enum getFieldMeta = T.fieldMeta;
	} else {
	enum TFieldMeta[] getFieldMeta = [];
	}
	}

	/**
	* Merges the field metadata array for D with the passed array.
	*/
	template mergeFieldMeta(T, alias fieldMetaData = cast(TFieldMeta[])null) {
	// Note: We don't use getFieldMeta here to avoid bug if it is instantiated
	// from TIsSetFlags, see comment there.
	static if (is(typeof(T.fieldMeta) == TFieldMeta[])) {
	enum mergeFieldMeta = T.fieldMeta ~ fieldMetaData;
	} else {
	enum TFieldMeta[] mergeFieldMeta = fieldMetaData;
	}
	}

	/**
	* Returns the field requirement level for T.name.
	*/
	template memberReq(T, string name, alias fieldMetaData = cast(TFieldMeta[])null) {
	enum memberReq = memberReqImpl!(T, name, fieldMetaData).result;
	}

	private {
	import std.algorithm : find;
	// DMD @@BUG@@: Missing import leads to failing build without error
	// message in unittest/debug/thrift/codegen/async_client.
	import std.array : empty, front;

	template memberReqImpl(T, string name, alias fieldMetaData) {
	enum meta = find!`a.name == b`(mergeFieldMeta!(T, fieldMetaData), name);
	static if (meta.empty \|\| meta.front.req == TReq.AUTO) {
	static if (isNullable!(MemberType!(T, name))) {
	enum result = TReq.OPTIONAL;
	} else {
	enum result = TReq.REQUIRED;
	}
	} else {
	enum result = meta.front.req;
	}
	}
	}


	template notIgnored(T, string name, alias fieldMetaData = cast(TFieldMeta[])null) {
	enum notIgnored = memberReq!(T, name, fieldMetaData) != TReq.IGNORE;
	}

	/**
	* Returns the method metadata array for T if any, or an empty array otherwise.
	*/
	template getMethodMeta(T) if (isService!T) {
	static if (is(typeof(T.methodMeta) == TMethodMeta[])) {
	enum getMethodMeta = T.methodMeta;
	} else {
	enum TMethodMeta[] getMethodMeta = [];
	}
	}


	/**
	* true if T.name is a member variable. Exceptions include methods, static
	* members, artifacts like package aliases, …
	*/
	template isValueMember(T, string name) {
	static if (!is(MemberType!(T, name))) {
	enum isValueMember = false;
	} else static if (
	is(MemberType!(T, name) == void) \|\|
	isSomeFunction!(MemberType!(T, name)) \|\|
	__traits(compiles, { return mixin("T." ~ name); }())
	) {
	enum isValueMember = false;
	} else {
	enum isValueMember = true;
	}
	}

	/**
	* Returns a tuple containing the names of the fields of T, not including
	* inherited fields. If a member is marked as TReq.IGNORE, it is not included
	* as well.
	*/
	template FieldNames(T, alias fieldMetaData = cast(TFieldMeta[])null) {
	alias StaticFilter!(
	All!(
	doesNotReadMembers,
	PApply!(isValueMember, T),
	PApply!(notIgnored, T, PApplySkip, fieldMetaData)
	),
	__traits(derivedMembers, T)
	) FieldNames;
	}

	/*
	* true if the passed member name is not a method generated by the
	* TStructHelpers template that in its implementations queries the struct
	* members.
	*
	* Kludge used internally to break a cycle caused a DMD forward reference
	* regression, see THRIFT-2130.
	*/
	enum doesNotReadMembers(string name) = !["opEquals", "thriftOpEqualsImpl",
	"toString", "thriftToStringImpl"].canFind(name);

	template derivedMembers(T) {
	alias TypeTuple!(__traits(derivedMembers, T)) derivedMembers;
	}

	template AllMemberMethodNames(T) if (isService!T) {
	alias NoDuplicates!(
	FilterMethodNames!(
	T,
	staticMap!(
	derivedMembers,
	TypeTuple!(T, InterfacesTuple!T)
	)
	)
	) AllMemberMethodNames;
	}

	template FilterMethodNames(T, MemberNames...) {
	alias StaticFilter!(
	CompilesAndTrue!(
	Compose!(isSomeFunction, TypeOf, PApply!(GetMember, T))
	),
	MemberNames
	) FilterMethodNames;
	}

	/**
	* Returns a type tuple containing only the elements of T for which the
	* eponymous template predicate pred is true.
	*
	* Example:
	* ---
	* alias StaticFilter!(isIntegral, int, string, long, float[]) Filtered;
	* static assert(is(Filtered == TypeTuple!(int, long)));
	* ---
	*/
	template StaticFilter(alias pred, T...) {
	static if (T.length == 0) {
	alias TypeTuple!() StaticFilter;
	} else static if (pred!(T[0])) {
	alias TypeTuple!(T[0], StaticFilter!(pred, T[1 .. $])) StaticFilter;
	} else {
	alias StaticFilter!(pred, T[1 .. $]) StaticFilter;
	}
	}

	/**
	* Binds the first n arguments of a template to a particular value (where n is
	* the number of arguments passed to PApply).
	*
	* The passed arguments are always applied starting from the left. However,
	* the special PApplySkip marker template can be used to indicate that an
	* argument should be skipped, so that e.g. the first and third argument
	* to a template can be fixed, but the second and remaining arguments would
	* still be left undefined.
	*
	* Skipping a number of parameters, but not providing enough arguments to
	* assign all of them during instantiation of the resulting template is an
	* error.
	*
	* Example:
	* ---
	* struct Foo(T, U, V) {}
	* alias PApply!(Foo, int, long) PartialFoo;
	* static assert(is(PartialFoo!float == Foo!(int, long, float)));
	*
	* alias PApply!(Test, int, PApplySkip, float) SkippedTest;
	* static assert(is(SkippedTest!long == Test!(int, long, float)));
	* ---
	*/
	template PApply(alias Target, T...) {
	template PApply(U...) {
	alias Target!(PApplyMergeArgs!(ConfinedTuple!T, U).Result) PApply;
	}
	}

	/// Ditto.
	template PApplySkip() {}

	private template PApplyMergeArgs(alias Preset, Args...) {
	static if (Preset.length == 0) {
	alias Args Result;
	} else {
	enum nextSkip = staticIndexOf!(PApplySkip, Preset.Tuple);
	static if (nextSkip == -1) {
	alias TypeTuple!(Preset.Tuple, Args) Result;
	} else static if (Args.length == 0) {
	// Have to use a static if clause instead of putting the condition
	// directly into the assert to avoid DMD trying to access Args[0]
	// nevertheless below.
	static assert(false,
	"PArgsSkip encountered, but no argument left to bind.");
	} else {
	alias TypeTuple!(
	Preset.Tuple[0 .. nextSkip],
	Args[0],
	PApplyMergeArgs!(
	ConfinedTuple!(Preset.Tuple[nextSkip + 1 .. $]),
	Args[1 .. $]
	).Result
	) Result;
	}
	}
	}

	unittest {
	struct Test(T, U, V) {}
	alias PApply!(Test, int, long) PartialTest;
	static assert(is(PartialTest!float == Test!(int, long, float)));

	alias PApply!(Test, int, PApplySkip, float) SkippedTest;
	static assert(is(SkippedTest!long == Test!(int, long, float)));

	alias PApply!(Test, int, PApplySkip, PApplySkip) TwoSkipped;
	static assert(!__traits(compiles, TwoSkipped!long));
	}


	/**
	* Composes a number of templates. The result is a template equivalent to
	* all the passed templates evaluated from right to left, akin to the
	* mathematical function composition notation: Instantiating Compose!(A, B, C)
	* is the same as instantiating A!(B!(C!(…))).
	*
	* This is especially useful for creating a template to use with staticMap/
	* StaticFilter, as demonstrated below.
	*
	* Example:
	* ---
	* template AllMethodNames(T) {
	* alias StaticFilter!(
	* CompilesAndTrue!(
	* Compose!(isSomeFunction, TypeOf, PApply!(GetMember, T))
	* ),
	* __traits(allMembers, T)
	* ) AllMethodNames;
	* }
	*
	* pragma(msg, AllMethodNames!Object);
	* ---
	*/
	template Compose(T...) {
	static if (T.length == 0) {
	template Compose(U...) {
	alias U Compose;
	}
	} else {
	template Compose(U...) {
	alias Instantiate!(T[0], Instantiate!(.Compose!(T[1 .. $]), U)) Compose;
	}
	}
	}

	/**
	* Instantiates the given template with the given list of parameters.
	*
	* Used to work around syntactic limiations of D with regard to instantiating
	* a template from a type tuple (e.g. T[0]!(...) is not valid) or a template
	* returning another template (e.g. Foo!(Bar)!(Baz) is not allowed).
	*/
	template Instantiate(alias Template, Params...) {
	alias Template!Params Instantiate;
	}

	/**
	* Combines several template predicates using logical AND, i.e. instantiating
	* All!(a, b, c) with parameters P for some templates a, b, c is equivalent to
	* a!P && b!P && c!P.
	*
	* The templates are evaluated from left to right, aborting evaluation in a
	* shurt-cut manner if a false result is encountered, in which case the latter
	* instantiations do not need to compile.
	*/
	template All(T...) {
	static if (T.length == 0) {
	template All(U...) {
	enum All = true;
	}
	} else {
	template All(U...) {
	static if (Instantiate!(T[0], U)) {
	alias Instantiate!(.All!(T[1 .. $]), U) All;
	} else {
	enum All = false;
	}
	}
	}
	}

	/**
	* Combines several template predicates using logical OR, i.e. instantiating
	* Any!(a, b, c) with parameters P for some templates a, b, c is equivalent to
	* a!P \|\| b!P \|\| c!P.
	*
	* The templates are evaluated from left to right, aborting evaluation in a
	* shurt-cut manner if a true result is encountered, in which case the latter
	* instantiations do not need to compile.
	*/
	template Any(T...) {
	static if (T.length == 0) {
	template Any(U...) {
	enum Any = false;
	}
	} else {
	template Any(U...) {
	static if (Instantiate!(T[0], U)) {
	enum Any = true;
	} else {
	alias Instantiate!(.Any!(T[1 .. $]), U) Any;
	}
	}
	}
	}

	template ConfinedTuple(T...) {
	alias T Tuple;
	enum length = T.length;
	}

	/*
	* foreach (Item; Items) {
	* List = Operator!(Item, List);
	* }
	* where Items is a ConfinedTuple and List is a type tuple.
	*/
	template ForAllWithList(alias Items, alias Operator, List...) if (
	is(typeof(Items.length) : size_t)
	){
	static if (Items.length == 0) {
	alias List ForAllWithList;
	} else {
	alias .ForAllWithList!(
	ConfinedTuple!(Items.Tuple[1 .. $]),
	Operator,
	Operator!(Items.Tuple[0], List)
	) ForAllWithList;
	}
	}

	/**
	* Wraps the passed template predicate so it returns true if it compiles and
	* evaluates to true, false it it doesn't compile or evaluates to false.
	*/
	template CompilesAndTrue(alias T) {
	template CompilesAndTrue(U...) {
	static if (is(typeof(T!U) : bool)) {
	enum bool CompilesAndTrue = T!U;
	} else {
	enum bool CompilesAndTrue = false;
	}
	}
	}