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Knowledge / Stack Overflow · hot matching “std”

2 shown · updated 2s ago · read only

Inconsistent return with std::expected and auto return (stackoverflow.com)stack

21 points by Romain in stackoverflow.com · 1h ago · stack

I am having a compile error I do not understand while using std::expected and auto return. Here is a simplified version of the code: #include <string> #include <tuple> #include <expected> std::expected<std::tuple<double,double,double,bool,bool>,std::string> func1(bool input){ if…
filed under c++auto c++23 std-expected
Why is `std::pair ` not designed to be trivially copyable? (stackoverflow.com)stack

19 points by xmllmx in stackoverflow.com · 2h ago · stack

If std::is_trivially_copyable_v<std::pair<int, int>> is true, then most implementations of std::vector can use the fastest std::memcpy to perform element relocations, providing a significant performance benefit. Why is std::pair<int, int> not designed to be trivially copyable?
filed under c++performance optimization std language-design