http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56032
Bug #: 56032
Summary: Uniform initialization of references
Classification: Unclassified
Product: gcc
Version: 4.7.1
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: xazax....@gmail.com
Consider the following code:
// ---- CODE ------
#include <iostream>
#include <vector>
class S {
public:
S(const std::vector<char>& v_) : v{v_} {}
void undefined() {
std::cout << v.front() << std::endl;
}
private:
const std::vector<char>& v;
};
int main(){
std::vector<char> foo {'f', 'a', 'i', 'l'};
std::cout << foo.front() << std::endl;
S s{foo};
s.undefined();
return 0;
}
// ---- END CODE ------
Compiled with: g++ -std=c++11 main.cpp
s.undefined(); prints invalid characters or crashes the executable.
I think the result of the problem is that, the: v{v_}
initialization creates a new temporary from the vector that is destroyed after
the execution leaves the scope of the constructor. ( This would only be the
intended behaviour in case v would be initialized from initializer list, but
{v_} is clearly not an initializer list here.)
If I replace the uniform initialization with regular one: v(v_)
the snippet above works as intended.
The very same snippet does not compile with gcc 4.5.2. Slightly related report
on that issue: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50025.
I guess the origin of this problem is the incomplete fix of the error above.
