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author | Remko Tronçon <git@el-tramo.be> | 2012-12-23 13:16:26 (GMT) |
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committer | Remko Tronçon <git@el-tramo.be> | 2012-12-23 14:43:26 (GMT) |
commit | 491ddd570a752cf9bda85933bed0c6942e39b1f9 (patch) | |
tree | 10c25c1be8cc08d0497df1dccd56a10fbb30beee /3rdParty/Boost/src/boost/lambda/detail/ret.hpp | |
parent | da7d7a0ca71b80281aa9ff2526290b61ccb0cc60 (diff) | |
download | swift-491ddd570a752cf9bda85933bed0c6942e39b1f9.zip swift-491ddd570a752cf9bda85933bed0c6942e39b1f9.tar.bz2 |
Update Boost to 1.52.0.
Change-Id: I1e56bea2600bf2ed9c5b3aba8c4f9d2a0f350e77
Diffstat (limited to '3rdParty/Boost/src/boost/lambda/detail/ret.hpp')
-rw-r--r-- | 3rdParty/Boost/src/boost/lambda/detail/ret.hpp | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/3rdParty/Boost/src/boost/lambda/detail/ret.hpp b/3rdParty/Boost/src/boost/lambda/detail/ret.hpp new file mode 100644 index 0000000..fbd8b3a --- /dev/null +++ b/3rdParty/Boost/src/boost/lambda/detail/ret.hpp @@ -0,0 +1,325 @@ +// Boost Lambda Library ret.hpp ----------------------------------------- + +// Copyright (C) 1999, 2000 Jaakko Jarvi (jaakko.jarvi@cs.utu.fi) +// +// Distributed under the Boost Software License, Version 1.0. (See +// accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) +// +// For more information, see www.boost.org + + +#ifndef BOOST_LAMBDA_RET_HPP +#define BOOST_LAMBDA_RET_HPP + +namespace boost { +namespace lambda { + + // TODO: + +// Add specializations for function references for ret, protect and unlambda +// e.g void foo(); unlambda(foo); fails, as it would add a const qualifier + // for a function type. + // on the other hand unlambda(*foo) does work + + +// -- ret ------------------------- +// the explicit return type template + + // TODO: It'd be nice to make ret a nop for other than lambda functors + // but causes an ambiguiyty with gcc (not with KCC), check what is the + // right interpretation. + + // // ret for others than lambda functors has no effect + // template <class U, class T> + // inline const T& ret(const T& t) { return t; } + + +template<class RET, class Arg> +inline const +lambda_functor< + lambda_functor_base< + explicit_return_type_action<RET>, + tuple<lambda_functor<Arg> > + > +> +ret(const lambda_functor<Arg>& a1) +{ + return + lambda_functor_base< + explicit_return_type_action<RET>, + tuple<lambda_functor<Arg> > + > + (tuple<lambda_functor<Arg> >(a1)); +} + +// protect ------------------ + + // protecting others than lambda functors has no effect +template <class T> +inline const T& protect(const T& t) { return t; } + +template<class Arg> +inline const +lambda_functor< + lambda_functor_base< + protect_action, + tuple<lambda_functor<Arg> > + > +> +protect(const lambda_functor<Arg>& a1) +{ + return + lambda_functor_base< + protect_action, + tuple<lambda_functor<Arg> > + > + (tuple<lambda_functor<Arg> >(a1)); +} + +// ------------------------------------------------------------------- + +// Hides the lambda functorness of a lambda functor. +// After this, the functor is immune to argument substitution, etc. +// This can be used, e.g. to make it safe to pass lambda functors as +// arguments to functions, which might use them as target functions + +// note, unlambda and protect are different things. Protect hides the lambda +// functor for one application, unlambda for good. + +template <class LambdaFunctor> +class non_lambda_functor +{ + LambdaFunctor lf; +public: + + // This functor defines the result_type typedef. + // The result type must be deducible without knowing the arguments + + template <class SigArgs> struct sig { + typedef typename + LambdaFunctor::inherited:: + template sig<typename SigArgs::tail_type>::type type; + }; + + explicit non_lambda_functor(const LambdaFunctor& a) : lf(a) {} + + typename LambdaFunctor::nullary_return_type + operator()() const { + return lf.template + call<typename LambdaFunctor::nullary_return_type> + (cnull_type(), cnull_type(), cnull_type(), cnull_type()); + } + + template<class A> + typename sig<tuple<const non_lambda_functor, A&> >::type + operator()(A& a) const { + return lf.template call<typename sig<tuple<const non_lambda_functor, A&> >::type >(a, cnull_type(), cnull_type(), cnull_type()); + } + + template<class A, class B> + typename sig<tuple<const non_lambda_functor, A&, B&> >::type + operator()(A& a, B& b) const { + return lf.template call<typename sig<tuple<const non_lambda_functor, A&, B&> >::type >(a, b, cnull_type(), cnull_type()); + } + + template<class A, class B, class C> + typename sig<tuple<const non_lambda_functor, A&, B&, C&> >::type + operator()(A& a, B& b, C& c) const { + return lf.template call<typename sig<tuple<const non_lambda_functor, A&, B&, C&> >::type>(a, b, c, cnull_type()); + } +}; + +template <class Arg> +inline const Arg& unlambda(const Arg& a) { return a; } + +template <class Arg> +inline const non_lambda_functor<lambda_functor<Arg> > +unlambda(const lambda_functor<Arg>& a) +{ + return non_lambda_functor<lambda_functor<Arg> >(a); +} + + // Due to a language restriction, lambda functors cannot be made to + // accept non-const rvalue arguments. Usually iterators do not return + // temporaries, but sometimes they do. That's why a workaround is provided. + // Note, that this potentially breaks const correctness, so be careful! + +// any lambda functor can be turned into a const_incorrect_lambda_functor +// The operator() takes arguments as consts and then casts constness +// away. So this breaks const correctness!!! but is a necessary workaround +// in some cases due to language limitations. +// Note, that this is not a lambda_functor anymore, so it can not be used +// as a sub lambda expression. + +template <class LambdaFunctor> +struct const_incorrect_lambda_functor { + LambdaFunctor lf; +public: + + explicit const_incorrect_lambda_functor(const LambdaFunctor& a) : lf(a) {} + + template <class SigArgs> struct sig { + typedef typename + LambdaFunctor::inherited::template + sig<typename SigArgs::tail_type>::type type; + }; + + // The nullary case is not needed (no arguments, no parameter type problems) + + template<class A> + typename sig<tuple<const const_incorrect_lambda_functor, A&> >::type + operator()(const A& a) const { + return lf.template call<typename sig<tuple<const const_incorrect_lambda_functor, A&> >::type >(const_cast<A&>(a), cnull_type(), cnull_type(), cnull_type()); + } + + template<class A, class B> + typename sig<tuple<const const_incorrect_lambda_functor, A&, B&> >::type + operator()(const A& a, const B& b) const { + return lf.template call<typename sig<tuple<const const_incorrect_lambda_functor, A&, B&> >::type >(const_cast<A&>(a), const_cast<B&>(b), cnull_type(), cnull_type()); + } + + template<class A, class B, class C> + typename sig<tuple<const const_incorrect_lambda_functor, A&, B&, C&> >::type + operator()(const A& a, const B& b, const C& c) const { + return lf.template call<typename sig<tuple<const const_incorrect_lambda_functor, A&, B&, C&> >::type>(const_cast<A&>(a), const_cast<B&>(b), const_cast<C&>(c), cnull_type()); + } +}; + +// ------------------------------------------------------------------------ +// any lambda functor can be turned into a const_parameter_lambda_functor +// The operator() takes arguments as const. +// This is useful if lambda functors are called with non-const rvalues. +// Note, that this is not a lambda_functor anymore, so it can not be used +// as a sub lambda expression. + +template <class LambdaFunctor> +struct const_parameter_lambda_functor { + LambdaFunctor lf; +public: + + explicit const_parameter_lambda_functor(const LambdaFunctor& a) : lf(a) {} + + template <class SigArgs> struct sig { + typedef typename + LambdaFunctor::inherited::template + sig<typename SigArgs::tail_type>::type type; + }; + + // The nullary case is not needed: no arguments, no constness problems. + + template<class A> + typename sig<tuple<const const_parameter_lambda_functor, const A&> >::type + operator()(const A& a) const { + return lf.template call<typename sig<tuple<const const_parameter_lambda_functor, const A&> >::type >(a, cnull_type(), cnull_type(), cnull_type()); + } + + template<class A, class B> + typename sig<tuple<const const_parameter_lambda_functor, const A&, const B&> >::type + operator()(const A& a, const B& b) const { + return lf.template call<typename sig<tuple<const const_parameter_lambda_functor, const A&, const B&> >::type >(a, b, cnull_type(), cnull_type()); + } + + template<class A, class B, class C> + typename sig<tuple<const const_parameter_lambda_functor, const A&, const B&, const C&> +>::type + operator()(const A& a, const B& b, const C& c) const { + return lf.template call<typename sig<tuple<const const_parameter_lambda_functor, const A&, const B&, const C&> >::type>(a, b, c, cnull_type()); + } +}; + +template <class Arg> +inline const const_incorrect_lambda_functor<lambda_functor<Arg> > +break_const(const lambda_functor<Arg>& lf) +{ + return const_incorrect_lambda_functor<lambda_functor<Arg> >(lf); +} + + +template <class Arg> +inline const const_parameter_lambda_functor<lambda_functor<Arg> > +const_parameters(const lambda_functor<Arg>& lf) +{ + return const_parameter_lambda_functor<lambda_functor<Arg> >(lf); +} + +// make void ------------------------------------------------ +// make_void( x ) turns a lambda functor x with some return type y into +// another lambda functor, which has a void return type +// when called, the original return type is discarded + +// we use this action. The action class will be called, which means that +// the wrapped lambda functor is evaluated, but we just don't do anything +// with the result. +struct voidifier_action { + template<class Ret, class A> static void apply(A&) {} +}; + +template<class Args> struct return_type_N<voidifier_action, Args> { + typedef void type; +}; + +template<class Arg1> +inline const +lambda_functor< + lambda_functor_base< + action<1, voidifier_action>, + tuple<lambda_functor<Arg1> > + > +> +make_void(const lambda_functor<Arg1>& a1) { +return + lambda_functor_base< + action<1, voidifier_action>, + tuple<lambda_functor<Arg1> > + > + (tuple<lambda_functor<Arg1> > (a1)); +} + +// for non-lambda functors, make_void does nothing +// (the argument gets evaluated immediately) + +template<class Arg1> +inline const +lambda_functor< + lambda_functor_base<do_nothing_action, null_type> +> +make_void(const Arg1& a1) { +return + lambda_functor_base<do_nothing_action, null_type>(); +} + +// std_functor ----------------------------------------------------- + +// The STL uses the result_type typedef as the convention to let binders know +// the return type of a function object. +// LL uses the sig template. +// To let LL know that the function object has the result_type typedef +// defined, it can be wrapped with the std_functor function. + + +// Just inherit form the template parameter (the standard functor), +// and provide a sig template. So we have a class which is still the +// same functor + the sig template. + +template<class T> +struct result_type_to_sig : public T { + template<class Args> struct sig { typedef typename T::result_type type; }; + result_type_to_sig(const T& t) : T(t) {} +}; + +template<class F> +inline result_type_to_sig<F> std_functor(const F& f) { return f; } + + +} // namespace lambda +} // namespace boost + +#endif + + + + + + + |