CPPAlliance

@CPPAlliance

Our mission is to make the C++ programming language accessible and useful to anyone who wishes to learn and apply the language.

CPPAlliance
@CPPAlliance
18h
int* p = &x; printf("%p", p); // ok std::cout << p; // ok std::format("{}", p); // error printf can format a pointer. iostream can format a pointer. std::format cannot 🧵👇
2
CPPAlliance
@CPPAlliance
Sep 3
filter_view caches the iterator from begin(). Call begin() again, it returns the cached position Now mutate the underlying range. The cached position may no longer satisfy the predicate Your next iteration silently skips elements or reads stale data. It's undefined behavior
1
CPPAlliance
@CPPAlliance
Sep 2
std::atomic protects shared data at runtime constexpr evaluates code at compile time. There are no threads at compile time So why would you want constexpr std::atomic? Because generic code shouldn't have to choose 🧵👇
1
CPPAlliance
@CPPAlliance
Sep 1
int x = 42, y = 42; std::reference_wrapper a{x}; std::reference_wrapper b{y}; a == b; // error reference_wrapper wraps a reference. But you can't compare two wrappers, even though the values they wrap are equal 🧵👇
2
CPPAlliance
@CPPAlliance
Aug 31
int a[] = {1, 2, 3}; int b[] = {1, 2, 3}; if (a == b) // false Same elements. Same order. Same size. The comparison returns false every single time C++ isn't comparing the arrays. It's comparing their addresses 🧵👇
5