{} initializer as expression

[Pierre Barbier de Reuille]

Hi,

I was wondering if this kind of things are valid as for the C++
standard? It is working with g++, but it may be either a bug (?) or an
"extension" ...

#include <iostream>

template <size_t N>
struct idx
{
typedef const size_t id[ N ];
void set( id i )
{
size_t j;
for( j = 0 ; j < N ; ++j )
{
i_[ j ] = i[ j ];
}
}

size_t i_[ N ];
};

int main()
{
typedef idx<4>::id id;
idx<4> i;
i.set( (id) {2,3,4,5} ); // Initializer used as expression
return 0;
}

Thanks,

Pierre

 

[Victor Bazarov]

I was wondering if this kind of things are valid as for the C++
standard? It is working with g++, but it may be either a bug (?) or an
"extension" ...

It's an extension. In the standard C++ there are no "compound literals"
(or whatever you prefer to name those things).

V

 

[Clark S. Cox III]

Hi,

I was wondering if this kind of things are valid as for the C++
standard? It is working with g++, but it may be either a bug (?) or an
"extension" ...

#include <iostream>

template <size_t N>
struct idx
{
typedef const size_t id[ N ];
void set( id i )
{
size_t j;
for( j = 0 ; j < N ; ++j )
{
i_[ j ] = i[ j ];
}
}

size_t i_[ N ];
};

int main()
{
typedef idx<4>::id id;
idx<4> i;
i.set( (id) {2,3,4,5} ); // Initializer used as expression
return 0;
}

It's an extension. GCC allows some C99-isms in C++ code as an extension.
http://gcc.gnu.org/onlinedocs/gcc-3.3.1/gcc/Compound-Literals.html