libstdc++-v3/testsuite/20_util/function/cons/noexcept.cc

   1 // { dg-do compile { target c++11 } }
   2 // { dg-require-effective-target hosted }
   3
   4 #include <functional>
   5
   6 struct X
   7 {
   8   void operator()(X*);
   9
  10   char bigness[100];
  11 };
  12
  13 using F = std::function<void(X*)>;
  14
  15 static_assert( std::is_nothrow_constructible<F>::value, "" );
  16 static_assert( std::is_nothrow_constructible<F, F>::value, "" );
  17 static_assert( ! std::is_nothrow_constructible<F, F&>::value, "" );
  18 static_assert( ! std::is_nothrow_constructible<F, const F&>::value, "" );
  19 static_assert( std::is_nothrow_constructible<F, std::nullptr_t>::value, "" );
  20
  21 static_assert( ! std::is_nothrow_constructible<F, X>::value, "" );
  22 using R = std::reference_wrapper<X>;
  23 static_assert( std::is_nothrow_constructible<F, R>::value, "" );
  24
  25
  26 // The standard requires that construction from a function pointer type
  27 // does not throw, but doesn't require that the construction is noexcept.
  28 // Strengthening that noexcept for these types is a GCC extension.
  29 static_assert( std::is_nothrow_constructible<F, void(*)(X*)>::value, "" );
  30 // This is a GCC extension, not required by the standard:
  31 static_assert( std::is_nothrow_constructible<F, void(&)(X*)>::value, "" );
  32 // This is a GCC extension, not required by the standard:
  33 static_assert( std::is_nothrow_constructible<F, void(X::*)()>::value, "" );
  34
  35 auto c = [](X*){};
  36 static_assert( std::is_nothrow_constructible<F, decltype(+c)>::value, "" );
  37 // The standard allows this to throw, but as a GCC extenension we store
  38 // closures with no captures in the std::function, so this is noexcept too:
  39 static_assert( std::is_nothrow_constructible<F, decltype(c)>::value, "" );