add missing constexpr to optional::value_or

[Credit to cpplearner]

Differential Revision: https://reviews.llvm.org/D27850

llvm-svn: 304813
This commit is contained in:
Casey Carter 2017-06-06 18:47:26 +00:00
parent 1e2b87893b
commit dd7c68bc78
2 changed files with 14 additions and 8 deletions

View File

@ -897,7 +897,7 @@ public:
template <class _Up>
_LIBCPP_INLINE_VISIBILITY
value_type value_or(_Up&& __v) &&
constexpr value_type value_or(_Up&& __v) &&
{
static_assert(is_move_constructible_v<value_type>,
"optional<T>::value_or: T must be move constructible");

View File

@ -10,7 +10,7 @@
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <optional>
// template <class U> T optional<T>::value_or(U&& v) &&;
// template <class U> constexpr T optional<T>::value_or(U&& v) &&;
#include <optional>
#include <type_traits>
@ -26,22 +26,22 @@ struct Y
{
int i_;
Y(int i) : i_(i) {}
constexpr Y(int i) : i_(i) {}
};
struct X
{
int i_;
X(int i) : i_(i) {}
X(X&& x) : i_(x.i_) {x.i_ = 0;}
X(const Y& y) : i_(y.i_) {}
X(Y&& y) : i_(y.i_+1) {}
constexpr X(int i) : i_(i) {}
constexpr X(X&& x) : i_(x.i_) {x.i_ = 0;}
constexpr X(const Y& y) : i_(y.i_) {}
constexpr X(Y&& y) : i_(y.i_+1) {}
friend constexpr bool operator==(const X& x, const X& y)
{return x.i_ == y.i_;}
};
int main()
constexpr int test()
{
{
optional<X> opt(in_place, 2);
@ -65,4 +65,10 @@ int main()
assert(std::move(opt).value_or(Y(3)) == 4);
assert(!opt);
}
return 0;
}
int main()
{
static_assert(test() == 0);
}