I was reading through the std::algorithm documentation at cppreference.com and I noticed a C++17 tag on a lot of cool things I haven't used yet. What got my attention most was the new execution policies. What I gathered from reading about them is that I can make any for_each loop I want multi-threaded just by specifying an execution policy.
For example, I have a program which outputs an image with a 2D graphic on it.
int main(){
std::for_each(
img.buffer().begin(),
img.buffer().end(),
renderer(
{-0.5, 0.0, 2.666, 2.0, M_PI / 2.0, 0.0},
img,
16
)
);
fout << img;
}
If I want to make this program multi-threaded I should be able to do it with one line.
int main(){
std::for_each(
std::execution::par_unseq, // c++17 feature
img.buffer().begin(),
img.buffer().end(),
renderer(
{-0.5, 0.0, 2.666, 2.0, M_PI / 2.0, 0.0},
img,
16
)
);
fout << img;
}
However when I first tried this (with g++ -std=c++17) I got an error telling me that ‘std::execution’ has not been declared, so I tried adding #include <execution> but it says execution: No such file or directory. I've also tried #include<experimental/algorithm> instead of #include<algorithm> but I get the same result. How do I use this new feature?
