Why is clang++ warning "suggest braces around initialization of subobject [-Wmissing-braces]"?

Question

I have this code:

#include <array>

int main(int, char **argv)
{
   std::array<int, 3> a = {1,2,3};
}

This compiles fine (-std=c++11) , but if you include -Wall it gives this warning that I don't understand:

clang_pp_error.cpp:5:28: warning: suggest braces around initialization of subobject [-Wmissing-braces]
   std::array<int, 3> a = {1,2,3};
                           ^~~~~
                           {    }

Answer 1

This should be a bug: https://llvm.org/bugs/show_bug.cgi?id=21629.

See also Is it wise to ignore gcc/clang's "-Wmissing-braces" warning?.

Answer 2

Use std::array<int, 3> a = {{1,2,3}}; instead.

See Why wasn't a double curly braces syntax preferred for constructors taking a std::initializer_list