mirror of
https://github.com/boostorg/config.git
synced 2025-11-04 01:31:37 +01:00
38 lines
1.0 KiB
Plaintext
38 lines
1.0 KiB
Plaintext
|
// (C) Copyright Mathias Gaunard 2009.
|
||
|
|
// Use, modification and distribution are subject to 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)
|
||
|
|
|
||
|
|
// See http://www.boost.org/libs/config for the most recent version.
|
||
|
|
|
||
|
|
// MACRO: BOOST_NO_SFINAE_EXPR
|
||
|
|
// TITLE: SFINAE for expressions
|
||
|
|
// DESCRIPTION: SFINAE for expressions not supported.
|
||
|
|
|
||
|
|
namespace boost_no_sfinae_expr
|
||
|
|
{
|
||
|
|
|
||
|
|
template<typename T>
|
||
|
|
struct has_foo
|
||
|
|
{
|
||
|
|
typedef char NotFound;
|
||
|
|
struct Found { char x[2]; };
|
||
|
|
|
||
|
|
template<int> struct dummy {};
|
||
|
|
|
||
|
|
template<class X> static Found test(dummy< sizeof((*(X*)0).foo(), 0) >*);
|
||
|
|
template<class X> static NotFound test( ... );
|
||
|
|
|
||
|
|
static const bool value = (sizeof(Found) == sizeof(test<T>(0)));
|
||
|
|
};
|
||
|
|
|
||
|
|
struct test1 {};
|
||
|
|
struct test2 { void foo(); };
|
||
|
|
|
||
|
|
int test()
|
||
|
|
{
|
||
|
|
return has_foo<test1>::value || !has_foo<test2>::value;
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace boost_no_sfinae_expr
|