std:: from_range, std:: from_range_t
From cppreference.com
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Defined in header
<ranges>
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||
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struct
from_range_t
{
explicit
from_range_t
(
)
=
default
;
}
;
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(since C++23) | |
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inline
constexpr
std
::
from_range_t
from_range
{
}
;
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(since C++23) | |
std::from_range
is a disambiguation tag that can be passed to the constructors of the suitable containers to indicate that the contained member is range constructed.
The corresponding type
std::from_range_t
can be used in the constructor's parameter list to match the intended tag.
Standard library
The following standard library types use
std::from_range_t
type in their constructors:
Containers library |
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(C++23)
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constructs the
vector
from a range
(public member function of
std::vector<T,Allocator>
)
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(C++26)
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constructs the
inplace_vector
from a range
(public member function of
std::inplace_vector<T,N>
)
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(C++23)
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constructs the
deque
from a range
(public member function of
std::deque<T,Allocator>
)
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(C++23)
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constructs the
forward_list
from a range
(public member function of
std::forward_list<T,Allocator>
)
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(C++23)
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constructs the
list
from a range
(public member function of
std::list<T,Allocator>
)
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(C++23)
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constructs the
set
from a range
(public member function of
std::set<Key,Compare,Allocator>
)
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(C++23)
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constructs the
map
from a range
(public member function of
std::map<Key,T,Compare,Allocator>
)
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(C++23)
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constructs the
multiset
from a range
(public member function of
std::multiset<Key,Compare,Allocator>
)
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(C++23)
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constructs the
multimap
from a range
(public member function of
std::multimap<Key,T,Compare,Allocator>
)
|
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(C++23)
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constructs the
unordered_set
from a range
(public member function of
std::unordered_set<Key,Hash,KeyEqual,Allocator>
)
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(C++23)
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constructs the
unordered_map
from a range
(public member function of
std::unordered_map<Key,T,Hash,KeyEqual,Allocator>
)
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(C++23)
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constructs the
unordered_multiset
from a range
(public member function of
std::unordered_multiset<Key,Hash,KeyEqual,Allocator>
)
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(C++23)
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constructs the
unordered_multimap
from a range
(public member function of
std::unordered_multimap<Key,T,Hash,KeyEqual,Allocator>
)
|
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(C++23)
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constructs the
priority_queue
from a range
(public member function of
std::priority_queue<T,Container,Compare>
)
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(C++23)
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constructs the
queue
from a range
(public member function of
std::queue<T,Container>
)
|
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(C++23)
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constructs the
stack
from a range
(public member function of
std::stack<T,Container>
)
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(C++23)
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constructs the
flat_set
from a range
(public member function of
std::flat_set<Key,Compare,KeyContainer>
)
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(C++23)
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constructs the
flat_map
from a range
(public member function of
std::flat_map<Key,T,Compare,KeyContainer,MappedContainer>
)
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(C++23)
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constructs the
flat_multiset
from a range
(public member function of
std::flat_multiset<Key,Compare,KeyContainer>
)
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(C++23)
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constructs the
flat_multimap
from a range
(public member function of
std::flat_multimap<Key,T,Compare,KeyContainer,MappedContainer>
)
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Strings library |
|
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(C++23)
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constructs the
basic_string
from a range
(public member function of
std::basic_string<CharT,Traits,Allocator>
)
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Notes
| Feature-test macro | Value | Std | Feature |
|---|---|---|---|
__cpp_lib_containers_ranges
|
202202L | (C++23) | Tagged constructors to construct from container compatible range |
Example
Run this code
#include <cassert> #include <string> int main() { #ifdef __cpp_lib_containers_ranges auto const range = {0x43, 43, 43}; std::string str{std::from_range, range}; // uses tagged constructor assert(str == "C++"); #endif }
See also
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in-place construction tag
(tag) |
|
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indicates that elements of a range are sorted (uniqueness is not required)
(tag) |
|
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(C++23)
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indicates that elements of a range are sorted and unique
(tag) |
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(C++23)
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constructs a new non-view object from an input range
(function template) |