Standard API

Standard Library Backports

C++ Standard versions include new language features and new library features. As the name implies, language features are new features of the language the require compiler support. Library features are simply new additions to the Standard Library that typically do not rely on new language features nor require compiler support and could conceivably be implemented in an older C++ Standard.

Typically, library features are only available in the particular C++ Standard version (or newer) in which they were introduced, even if the library features do not depend on any particular language features.

In effort to make library features available to a broader set of users, the NVIDIA C++ Standard Library relaxes this restriction. libcu++ makes a best-effort to provide access to C++ Standard Library features in older C++ Standard versions than they were introduced. For example, the calendar functionality added to <chrono> in C++20 is made available in C++14.

Feature availability:

• C++17 and C++20 features of<chrono> available in C++14:

  • calendar functionality, e.g., year,month,day,year_month_day

  • duration functions, e.g., floor, ceil, round

  • Note: Timezone and clocks added in C++20 are not available

• C++17 features from <type_traits> available in C++14:

  • Convenience _v aliases such as is_same_v

  • void_t

  • Trait operations: conjunction,negation,disjunction

  • invoke_result

• C++17 <optional> is available in C++14

  • all features are available in C++14 and at compile time if the payload type permits it

• C++17 <variant> is available in C++14

  • all features are available in C++14 and at compile time if the payload types permit it

• C++17/20 constexpr <array> is available in C++14.

  • all operation on array are made constexpr in C++14 with exception of {c}rbegin and {c}rend, which requires C++17.

• C++20 constexpr <complex> is available in C++14.

  • all operation on complex are made constexpr if is_constant_evaluated is supported.

• C++20 <concepts> are available in C++14.

  • all standard concepts are available in C++14 and C++17. However, they need to be used similar to type traits as language concepts are not available.

• C++20 std::assume_aligned in <memory> is available in C++11.

• C++20 <ranges> are available in C++17.

  • all <ranges> concepts are available in C++17. However, they need to be used similar to type traits as language concepts are not available.

  • range algorithms are not implemented.

  • views are not implemented.

• C++20 and C++26 <span> is mostly available in C++14.

  • With the exception of the range based constructors all features are available in C++14 and C++17. The range based constructors are emulated but not 100% equivalent.

• C++20 features of <functional> have been partially ported to C++17.

  • bind_front is available in C++17.

• C++20 integer comparison functions in <utility> are available in C++11.

• C++23 byteswap in <bit> is available in C++11.

• C++23 <expected> is available in C++14.

  • all features are available in C++14

• C++23 invoke_r in <functional> is available in C++14.

• C++23 <mdspan> is available in C++14.

  • mdspan is feature complete in C++14 onwards.

  • mdspan on msvc is only supported in C++20 and onwards.

• C++26 std::dims is available in C++14.

• C++23 forward_like, to_underlying and unreachable from <utility> are available in C++11.

• C++23 is_scoped_enum in <type_traits> is available in C++11.

• C++26 tuple protocol to complex is available in C++11.