Here, I keep a note list of C++ features that I find interesting or useful. Beware that I've written those notes down on the fly as I understood them and my understanding might be incomplete or incorrect!
Source:
A list (to have them in one place), source/inspiration:
noreturn, deprecated("description"), fallthrough, (un)likely,
maybe_unused (be careful)
carries_dependencyrelease/acquire dependency passingkill_dependency to undonodiscardno_unique_addressmsvc::no_unique_address for MSVCassume(predicate expr)std::boolalpha - to print true/false instead of 1/0
The initial parts are particularly useful if you'd like to refresh on the parameter pack syntax and folds.
Multilambdas are (I think) also explained in Jason Turner's C++ weekly series, as well as fold expressions.
From their about page:
C++ Insights is a clang-based tool which does a source to source transformation. Its goal is to make things visible, which normally and intentionally happen behind the scenes. It's about the magic the compiler does for us to make things work. Or looking through the classes of a compiler.
this
class C {
void f(this C& self) {}
// deducing this
template <class C>
auto&& g(this C&& self) {}
}
if constevalif consteval { A } else { B }
() and before () - behind [] - for attribute on the call - e.g. [[nodiscard]])uz and UZ literals for std::size_tauto(x) and auto{x} to get prvalueswarning, elifdef and elifndef preprocessor directivesstd::unreachable - invoking this at runtime invokes UB (optimizations)[[assume(expr)]] syntax for assumptionsU'\N{GREEK CAPITAL LETTER DELTA}'std::optionaltransform, and_then, or_elsestarts_with, ends_withshift_left, shift_right, find_last(_if/_if_not) => subrange or {last, last}cotnains (element), contains_subrangeto - ranges to containersauto set{ std::ranges::to<std::set>(vectorData) };auto set { vectorData | std::ranges::to<std::set<double>() };auto set {std::from_range, vectorData}fold_left, fold_rightfold_left_first, fold_right_lastfold_left_with_iter, fold_left_first_with_iterzip and zip_transformadjacent<WINDOW_SIZE> and adjacent_transform
pairwise and pairwise_transform as adjacent<2>slide - like adjacent but with a runtime window sizechunk - like slide but the window is not sliding, but jumping
chunk_by - with a predicate where to make the cutjoin_with!!!stride(n) skips elementsrepeat - bounded or unboundedcartesian_productas_rvalue - std::move, the viewstd::expectedhas_value, value (throws), error, error_valuestd::optionalstd::print, println - it's even faster!
format) for ranges
{}, {::}, {:n}, {:n:n:*^4}import std;flat_map, ... - adapters over containers
mdspan - layout policy -> N-dimensional coordinates -> 1D indexgenerator - coroutine-based
string::conatins!!!string::resize_and_overwrite(count, op) - resize and initialize potential new elements with op(data, neededCount)
<stacktrace>!!!std::move_only_function<F>spanstream - stream operations on external buffers
ispanstream, ospanstreambyteswap!!!to_underlying -> enum to underlying_type_t[i = 1]() mutable { i += 2; return i; } - mutable lambda with state (state is reused accross calls)
3rd June 2024