Viewing file:  Wredundant-move1.C (1.78 KB) -rw-r--r--
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// PR c++/87029
// { dg-do compile { target c++11 } }
// { dg-options "-Wredundant-move" }
// Define std::move.
namespace std {
template<typename _Tp>
struct remove_reference
{ typedef _Tp type; };
template<typename _Tp>
struct remove_reference<_Tp&>
{ typedef _Tp type; };
template<typename _Tp>
struct remove_reference<_Tp&&>
{ typedef _Tp type; };
template<typename _Tp>
constexpr typename std::remove_reference<_Tp>::type&&
move(_Tp&& __t) noexcept
{ return static_cast<typename std::remove_reference<_Tp>::type&&>(__t); }
}
struct T {
T() { }
T(const T&) { }
T(T&&) { }
};
struct U {
U() { }
U(const U&) { }
U(U&&) { }
U(T) { }
};
T
fn1 (T t)
{
return t;
}
T
fn2 (T t)
{
// Will use move even without std::move.
return std::move (t); // { dg-warning "redundant move in return statement" }
}
T
fn3 (const T t)
{
// t is const: will decay into copy.
return t;
}
T
fn4 (const T t)
{
// t is const: will decay into copy despite std::move, so it's redundant.
// We used to warn about this, but no longer since c++/87378.
return std::move (t); // { dg-warning "redundant move" "" { target c++20 } }
}
int
fn5 (int i)
{
// Not a class type.
return std::move (i);
}
T
fn6 (T t, bool b)
{
if (b)
throw std::move (t);
return std::move (t); // { dg-warning "redundant move in return statement" }
}
U
fn7 (T t)
{
// Core 1579 means we'll get a move here.
return t;
}
U
fn8 (T t)
{
// Core 1579 means we'll get a move here. Even without std::move.
return std::move (t); // { dg-warning "redundant move in return statement" }
}
T
fn9 (T& t)
{
// T is a reference and the move isn't redundant.
return std::move (t);
}
T
fn10 (T&& t)
{
// T is a reference and the move isn't redundant.
return std::move (t);
}
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