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| Sequence | ||||
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| Associative | ||||
| Unordered associative | ||||
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| Adaptors | ||||
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| Views | ||||
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| Tables | ||||
| Iterator invalidation | ||||
| Member function table | ||||
| Non-member function table |
| Member functions | ||||
| Element access | ||||
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| Iterators | ||||
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as_bytesas_writable_bytes | ||||
| Non-member constant | ||||
| Deduction guides |
Defined in header <span> | ||
template<class T,std::size_t N> std::span<conststd::byte, S/* see below */> | (1) | (since C++20) |
template<class T,std::size_t N> std::span<std::byte, S/* see below */> | (2) | (since C++20) |
Obtains a view to the object representation of the elements of the spans.
IfN isstd::dynamic_extent, the extent of the returned spanS is alsostd::dynamic_extent; otherwise it issizeof(T)* N.
as_writable_bytes only participates in overload resolution ifstd::is_const_v<T> isfalse.
#include <cstddef>#include <iomanip>#include <iostream>#include <span> void print(floatconst x,std::span<conststd::byte>const bytes){std::cout<<std::setprecision(6)<<std::setw(8)<< x<<" = { "<<std::hex<<std::uppercase<<std::setfill('0');for(autoconst b: bytes)std::cout<<std::setw(2)<<std::to_integer<int>(b)<<' ';std::cout<<std::dec<<"}\n";} int main(){/* mutable */float data[1]{3.141592f}; autoconst const_bytes= std::as_bytes(std::span{data}); print(data[0], const_bytes); autoconst writable_bytes= std::as_writable_bytes(std::span{data}); // Change the sign bit that is the MSB (IEEE 754 Floating-Point Standard). writable_bytes[3]|=std::byte{0B1000'0000}; print(data[0], const_bytes);}
Possible output:
3.14159 = { D8 0F 49 40 }-3.14159 = { D8 0F 49 C0 }| implicitly creates objects in given storage with the object representation reused (function template)[edit] | |
(C++17) | the byte type (enum)[edit] |
