Hello! where is a code that compiles and works as expected: #include <atomic> #include <iostream> int main() { std::atomic<int> i(0); i += 3; std::cout << i << std::endl; } http://liveworkspace.org/code/eb92d1706687414dd3f49976584ff337 now change it to type double: #include <atomic> #include <iostream> int main() { std::atomic<double> i(0); i += 3.14; std::cout << i << std::endl; } http://liveworkspace.org/code/555191936a23b06352220ff11b1e33df and get the following error: > source.cpp: In function 'int main()': > source.cpp:6:9: error: no match for 'operator+=' in 'i += 3.1400000000000001e+0' therefore, I have two questions: 1. сan double be actually an atomic type? 2. how is supposed to use atomic <double> by standard? Thanks! -- Regards, niXman