#include <atomic>
std::atomic<int> outside(1);
class A{
std::atomic<int> inside(1); // <--- why not allowed ?
};
prog.cpp:4:25: error: expected identifier before numeric constant
prog.cpp:4:25: error: expected ',' or '...' before numeric constant
In VS11
C2059: syntax error : 'constant'
In-class initializers do not support the (e) syntax of initialization because the committee members that designed it worried about potential ambiguities (For example, the well-known T t(X()); declaration would be ambiguous and does not specify an initialization but declares a function with an unnamed parameter).
You can say
class A{
std::atomic<int> inside{1};
};
Alternatively a default value can be passed in the constructor
class A {
A():inside(1) {}
std::atomic<int> inside;
};
()inside the class. Have you tried=instead of braces ?