23 General utilities library [utilities]

23.1 General [utilities.general]

This Clause describes utilities that are generally useful in C++ programs; some of these utilities are used by other elements of the C++ standard library.
These utilities are summarized in Table 34.
Table 34 — General utilities library summary
Subclause
Header(s)
Utility components
<utility>
Compile-time integer sequences
<utility>
Pairs
<utility>
Tuples
<tuple>
Optional objects
<optional>
Variants
<variant>
Storage for any type
<any>
Fixed-size sequences of bits
<bitset>
Memory
<memory>
<cstdlib>
Smart pointers
<memory>
Memory resources
<memory_­resource>
Scoped allocators
<scoped_­allocator>
Function objects
<functional>
Type traits
<type_­traits>
Compile-time rational arithmetic
<ratio>
Time utilities
<chrono>
<ctime>
Type indexes
<typeindex>
Execution policies
<execution>