https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82247
Bug ID: 82247
Summary: [concepts] Name deduction in concepts fails depending
on the argument type
Product: gcc
Version: 7.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: mjklaim at gmail dot com
Target Milestone: ---
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <string>
#include <vector>
template <typename T>
bool concept Fooable = requires(const T& t) {
{ foo(t) }; // foo is unknown here
};
template <typename T>
void foo(T&& t) {
}
template <Fooable T>
void bar(T&& t)
{
}
class K
{
int x = 0;
};
class WTF
{
std::vector<int> values;
};
int main() {
// int i{}; // FAIL
// K i; // SUCCEED
// float i; // FAIL
// std::string i; // FAIL?????
// std::vector<int> i; // FAIL?????
// auto i =[]{}; // SUCCEED
// int i[42]; // FAIL
// int* i = nullptr;
WTF i; // SUCCEED HAHAHAHA
bar(i);
}~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
All these lines should have succeded, but only using the custom types worked.
I have no idea what is wrong here but it seem that even for int, the deduction
of the foo function is not done at the right time.
