use of [ ` std::weak_ptr ` ](/w/cpp/memory/weak_ptr "cpp/memory/weak ptr") as keys in unordered associative containers  |  [ P1901R2 ](https://wg21.link/P1901R2) |  |  |  |  |  |  |   
Native handles in file streams  |  [ P1759R6 ](https://wg21.link/P1759R6) |  14  |  18  |  |  |  |  |   
Interfacing string streams with [ ` std::string_view ` ](/w/cpp/string/basic_string_view "cpp/string/basic string view") |  [ P2495R3 ](https://wg21.link/P2495R3) |  |  19  |  |  |  |  |   
Interfacing [ ` std::bitset ` ](/w/cpp/utility/bitset "cpp/utility/bitset") with [ ` std::string_view ` ](/w/cpp/string/basic_string_view "cpp/string/basic string view") |  [ P2697R1 ](https://wg21.link/P2697R1) |  |  18  |  |  |  |  |   
More constexpr for [ ` <cmath> ` ](/w/cpp/header/cmath "cpp/header/cmath") and [ ` <complex> ` ](/w/cpp/header/complex "cpp/header/complex") |  [ P1383R2 ](https://wg21.link/P1383R2) |  4.6 (partial)*  |  |  |  |  |  |   
Adding the new 2022 SI prefixes on ratios:  std::quecto  ,  std::ronto  ,  std::ronna  , and  std::quetta  |  [ P2734R0 ](https://wg21.link/P2734R0) |  14  |  17  |  |  |  |  |   
std::function_ref  : type-erased callable reference  |  [ P0792R14 ](https://wg21.link/P0792R14) |  |  |  |  |  |  |   
std::copyable_function  |  [ P2548R6 ](https://wg21.link/P2548R6) |  |  |  |  |  |  |   
[ ` std::bind_front ` ](/w/cpp/utility/functional/bind_front "cpp/utility/functional/bind front") , [ ` std::bind_back ` ](/w/cpp/utility/functional/bind_front "cpp/utility/functional/bind front") , and [ ` std::not_fn ` ](/w/cpp/utility/functional/not_fn "cpp/utility/functional/not fn") to NTTP callables  |  [ P2714R1 ](https://wg21.link/P2714R1) |  |  |  |  |  |  |   
std::submdspan()  |  [ P2630R4 ](https://wg21.link/P2630R4) |  |  |  |  |  |  |   
Freestanding Language: Optional [ ` ::operator new ` ](/w/cpp/memory/new/operator_new "cpp/memory/new/operator new") |  [ P2013R5 ](https://wg21.link/P2013R5) |  |  |  N/A  |  |  |  |   
[ Saturation Arithmetic ](/w/cpp/numeric#Saturation_arithmetic_.28since_C.2B.2B26.29 "cpp/numeric") |  [ P0543R3 ](https://wg21.link/P0543R3) |  14  |  18  |  |  |  |  |   
[ ` <debugging> ` ](/w/cpp/header/debugging "cpp/header/debugging") : Debugging Support  |  [ P2546R5 ](https://wg21.link/P2546R5)   
[ P2810R3 ](https://wg21.link/P2810R3) |  |  |  |  |  |  |   
[ ` <linalg> ` ](/w/cpp/header/linalg "cpp/header/linalg") : A free function linear algebra interface based on the BLAS  |  [ P1673R13 ](https://wg21.link/P1673R13) |  |  |  |  |  |  |   
Making  [ assert() ](/w/cpp/error/assert "cpp/error/assert") macro user friendly  |  [ P2264R7 ](https://wg21.link/P2264R7) |  |  |  |  |  |  |   
Runtime format strings  |  [ P2918R2 ](https://wg21.link/P2918R2) |  14  |  18  |  |  |  |  |   
std::span  over an initializer list  |  [ P2447R4 ](https://wg21.link/P2447R4) |  |  18  |  |  |  |  |   
std::span::at()  |  [ P2821R5 ](https://wg21.link/P2821R5) |  14  |  18  |  |  |  |  |   
Added tuple protocol to  [ std::complex ](/w/cpp/numeric/complex "cpp/numeric/complex") |  [ P2819R2 ](https://wg21.link/P2819R2) |  |  19  |  |  |  |  |   
A new specification for  [ std::generate_canonical ](/w/cpp/numeric/random/generate_canonical "cpp/numeric/random/generate canonical") |  [ P0952R1 ](https://wg21.link/P0952R1) |  |  |  |  |  |  |   
Removing deprecated typedef  std::allocator::is_always_equal  |  [ P2868R1 ](https://wg21.link/P2868R1) |  |  18  |  |  |  |  |   
Removing function overload of  [ std::basic_string::reserve() ](/w/cpp/string/basic_string/reserve "cpp/string/basic string/reserve") that takes no argument  |  [ P2870R3 ](https://wg21.link/P2870R3) |  |  18  |  |  |  |  |   
Remove deprecated Unicode conversion facets ( [ ` <codecvt> ` ](/w/cpp/header/codecvt "cpp/header/codecvt") )  |  [ P2871R3 ](https://wg21.link/P2871R3) |  |  18  |  |  |  |  |   
Freestanding: removing  [ std::strtok ](/w/cpp/string/byte/strtok "cpp/string/byte/strtok") |  [ P2937R0 ](https://wg21.link/P2937R0) |