20 General utilities library [utilities]

20.1 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 41.
Table 41: General utilities library summary   [tab:utilities.summary]
Subclause
Header
Utility components
<utility>
Compile-time integer sequences
Pairs
Tuples
<tuple>
Optional objects
<optional>
Variants
<variant>
Storage for any type
<any>
Fixed-size sequences of bits
<bitset>
Memory
<cstdlib>, <memory>
Smart pointers
<memory>
Memory resources
<memory_­resource>
Scoped allocators
<scoped_­allocator>
Function objects
<functional>
Type traits
<type_­traits>
Compile-time rational arithmetic
<ratio>
Type indexes
<typeindex>
Execution policies
<execution>
Primitive numeric conversions
<charconv>
Formatting
<format>