https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103543
Bug ID: 103543
Summary: Potential compiler warning for return of temporary?
Product: gcc
Version: 11.2.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: gcc at hazlewoods dot net
Target Milestone: ---
A return of a temporary from a lambda assigned to `std::function<>` does not
cause a warning, unlike a regular function.
Would be useful if it trapped, but it may be too far down the deduction path.
<code>
#include <iostream>
#include <functional>
struct S
{
int s{};
};
using F = std::function<S const& ()>;
S const& fn()
{
return S{}; // Warning: returning ref to temporary
}
int main()
{
F f = [](){ return S{}; }; // No warning
std::cout << f().s << std::endl; // Ouch
}
</code>
g++-11 -W -Wall -std=c++20 -O2 -pedantic-errors test.cpp --save-temps
g++-11 --version
g++-11 (GCC) 11.2.1 20211105
