nce.com/mwiki/index.php?title=Template:cpp/utility/dsc_expected&action=edit)  
Defined in header ` [ <variant> ](/w/cpp/header/variant "cpp/header/variant")
`  
[ variant  ](/w/cpp/utility/variant "cpp/utility/variant") (C++17)  |  a type-safe discriminated union   
(class template)  [ [edit]
](https://en.cppreference.com/mwiki/index.php?title=Template:cpp/utility/dsc_variant&action=edit)  
Defined in header ` [ <any> ](/w/cpp/header/any "cpp/header/any") `  
[ any  ](/w/cpp/utility/any "cpp/utility/any") (C++17)  |  objects that hold instances of any [ CopyConstructible  ](/w/cpp/named_req/CopyConstructible "cpp/named req/CopyConstructible") type   
(class)  [ [edit]
](https://en.cppreference.com/mwiki/index.php?title=Template:cpp/utility/dsc_any&action=edit)  
Defined in header ` [ <utility> ](/w/cpp/header/utility "cpp/header/utility")
`  
[ in_place  in_place_type  in_place_index  in_place_t  in_place_type_t  in_place_index_t  ](/w/cpp/utility/in_place "cpp/utility/in place") (C++17)  |  in-place construction tag   
(tag)  [ [edit]
](https://en.cppreference.com/mwiki/index.php?title=Template:cpp/utility/dsc_in_place&action=edit)  
  
###  [ [ edit ](/mwiki/index.php?title=cpp/utility&action=edit&section=22
"Edit section: Bitset") ]  [ Bitset ](/w/cpp/utility/bitset
"cpp/utility/bitset")

Defined in header ` [ <bitset> ](/w/cpp/header/bitset "cpp/header/bitset") `  
---  
[ bitset  ](/w/cpp/utility/bitset "cpp/utility/bitset") |  implements constant length bit array   
(class template)  [ [edit]
](https://en.cppreference.com/mwiki/index.php?title=Template:cpp/utility/dsc_bitset&action=edit)  
  
###  [ [ edit ](/mwiki/index.php?title=cpp/utility&action=edit&section=23
"Edit section: Function objects") ]  [ Function objects
](/w/cpp/utility/functional "cpp/utility/functional")

Partial function application (e.g.  [ std::bind
](/w/cpp/utility/functional/bind "cpp/utility/functional/bind") ) and related
utilities: utilities for binding such as  [ std::ref
](/w/cpp/utility/functional/ref "cpp/utility/functional/ref") and  [
std::placeholders ](/w/cpp/utility/functional/placeholders
"cpp/utility/functional/placeholders") , polymorphic function wrappers:  [
std::function ](/w/cpp/utility/functional/function
"cpp/utility/functional/function") , predefined functors (e.g.  [ std::plus
](/w/cpp/utility/functional/plus "cpp/utility/functional/plus") ,  [
std::equal_to ](/w/cpp/utility/functional/equal_to
"cpp/utility/functional/equal to") ), pointer-to-member to function converters
[ std::mem_fn ](/w/cpp/utility/functional/mem_fn "cpp/utility/functional/mem
fn") .

###  [ [ edit ](/mwiki/index.php?title=cpp/utility&action=edit&section=24
"Edit section: Hash support") ]  [ Hash support ](/w/cpp/utility/hash
"cpp/utility/hash")

Defined in header ` [ <functional> ](/w/cpp/header/functional
"cpp/header/functional") `  
---  
[ hash  ](/w/cpp/utility/hash "cpp/utility/hash") (C++11)  |  hash function object   
(class template)  [ [edit]
](https://en.cppreference.com/mwiki/index.php?title=Template:cpp/utility/dsc_hash&action=edit)  
  
###  [ [ edit ](/mwiki/index.php?title=cpp/utility&action=edit&section=25
"Edit section: Date and time") ]  [ Date and time ](/w/cpp/chrono
"cpp/chrono")

Time tracking (e.g.  [ std::chrono::time_point ](/w/cpp/chrono/time_point
"cpp/chrono/time point") ,  [ std::chrono::duration ](/w/cpp/chrono/duration
"cpp/chrono/duration") ), C-style date and time (e.g.  [ std::time
](/w/cpp/chrono/c/time "cpp/chrono/c/time") ,  [ std::clock
](/w/cpp/chrono/c/clock "cpp/chrono/c/clock") )

###  [ [ edit ](/mwiki/index.php?title=cpp/utility&action=edit&section=26
"Edit section: Elementary string conversions") ]  Elementary string
conversions

In addition to sophisticated locale-dependent parsers and formatters provided
by the [ C++ I/O ](/w/cpp/io "cpp/io") library, the [ C I/O ](/w/cpp/io/c
"cpp/io/c") library, [ C++ string converters
](/w/cpp/string/basic_string#Numeric_conversions "cpp/string/basic string") ,
and [ C s