https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61961
Bug ID: 61961
Summary: New warning when initializer-list constructor chosen
for uniform init that doesn't mean to use
initializer_list
Product: gcc
Version: 4.10.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: redi at gcc dot gnu.org
#include <string>
int main()
{
std::string s{1ul, 'a'};
}
It would be nice to get a warning here that the initializer-list constructor
was chosen rather than the string(size_type, value_type) constructor.
The semantics I suggest are to warn when:
* an initializer-list constructor is selected by overload resolution
* the elements of the braced-init-list are not all the same type
* another (non-initializer-list) constructor is viable
So no warnings for:
std::string{'a', 'b'} // elements are same type
std::string{'0'+(x%10), '0'+(y%10)} // elements are same type
std::string{'a', 'b', 'c', 'd', 0} // no other viable constructor
std::string{1ul, '0'+(x%10)} // use char('0'+(x%10)) to get warning
but warnings for:
std::string(1ul, 'a'} // motivating case
std::string{'a', 0} // use '\0' to suppress warning
