std::tuple_size<std::complex>
From cppreference.com
Defined in header <complex>
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template< class T > struct tuple_size<std::complex<T>> |
(since C++26) | |
The partial specialization of std::tuple_size for std::complex provides a compile-time way to obtain the number of components of a complex
, which is always 2, using tuple-like syntax. It is provided for structured binding support.
Contents |
Inherited from std::integral_constant
Member constants
value [static] |
the constant value 2 (public static member constant) |
Member functions
operator std::size_t |
converts the object to std::size_t, returns value (public member function) |
operator() (C++14) |
returns value (public member function) |
Member types
Type | Definition |
value_type
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std::size_t |
type
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std::integral_constant<std::size_t, value> |
[edit] Notes
Feature-test macro | Value | Std | Feature |
---|---|---|---|
__cpp_lib_tuple_like |
202311L | (C++26) | Add tuple protocol to std::complex |
[edit] Example
Run this code
#include <complex> static_assert(std::tuple_size_v<std::complex<float>> == 2); static_assert([] { using namespace std::literals; auto [re, im] = -1.5 + 2.5i; return re == -1.5 && im == 2.5; }()); static_assert([] { using namespace std::literals; auto z = std::complex<double>{}; auto& [re, im] = z; re = 1.0; im = 2.0; return z == 1.0 + 2.0i; }()); int main() {}
[edit] See also
Structured binding (C++17) | binds the specified names to sub-objects or tuple elements of the initializer |
(C++11) |
obtains the number of elements of a tuple-like type (class template) |
obtains the underlying real and imaginary number type of a std::complex (class template specialization) | |
(C++26) |
obtains a reference to real or imaginary part from a std::complex (function template) |