Dune::Std Namespace Reference

Namespace for features backported from new C++ standards. More...

Classes
struct	compare_three_way
	A functor implementing the three-way comparison on the arguments. More...
class	default_accessor
	A type for indexed access to elements of mdspan. More...
class	extents
	Multidimensional index space with dynamic and static extents. More...
struct	identity
	A function object type whose operator() returns its argument unchanged. More...
struct	layout_left
	A layout where the leftmost extent has stride 1. More...
struct	layout_right
	A layout where the rightmost extent has stride 1, and strides increase right-to-left as the product of extents. More...
struct	layout_stride
	A layout mapping where the strides are user-defined. More...
class	mdarray
	An owning multi-dimensional array analog of mdspan. More...
class	mdspan
	A multi-dimensional non-owning array view. More...
struct	nonesuch
	Type representing a lookup failure by std::detected_or and friends. More...
class	span
	A contiguous sequence of elements with static or dynamic extent. More...

Concepts
concept	three_way_comparable
	The concept std::three_way_comparable specifies that the three way comparison operator <=> on T yield results consistent with the comparison category implied by Cat.
concept	three_way_comparable_with
	The concept std::three_way_comparable_with specifies that the three way comparison operator <=> on (possibly mixed) T and U operands yield results consistent with the comparison category implied by Cat. Comparing mixed operands yields results equivalent to comparing the operands converted to their common type.
concept	indirectly_copyable
	The std::indirectly_copyable concept specifies the relationship between an indirectly_readable type and a type that is indirectly_writable. The indirectly_writable type must be able to directly copy the object that the indirectly_readable type references.

Typedefs
template<class IndexType , std::size_t R>
using	dextents = typename Impl::DExtentsImpl< IndexType, std::make_integer_sequence< std::size_t, R > >::type
	Alias of extents of given rank R and purely dynamic extents. See [mdspan.extents.dextents].
template<typename Default , template< typename... > class Op, typename... Args>
using	detected_or = Impl::detector< Default, void, Op, Args... >
	Detects whether Op<Args...> is valid and makes the result available. More...
template<template< typename... > class Op, typename... Args>
using	is_detected = typename detected_or< nonesuch, Op, Args... >::value_t
	Detects whether Op<Args...> is valid. More...
template<template< typename... > class Op, typename... Args>
using	detected_t = typename detected_or< nonesuch, Op, Args... >::type
	Returns Op<Args...> if that is valid; otherwise returns nonesuch. More...
template<typename Default , template< typename... > class Op, typename... Args>
using	detected_or_t = typename detected_or< Default, Op, Args... >::type
	Returns Op<Args...> if that is valid; otherwise returns the fallback type Default. More...
template<typename Expected , template< typename... > class Op, typename... Args>
using	is_detected_exact = std::is_same< Expected, detected_t< Op, Args... > >
	Checks whether Op<Args...> is Expected without causing an error if Op<Args...> is invalid. More...
template<typename Target , template< typename... > class Op, typename... Args>
using	is_detected_convertible = std::is_convertible< Target, detected_t< Op, Args... > >
	Checks whether Op<Args...> is convertible to Target without causing an error if Op<Args...> is invalid. More...

Functions
template<class I1 , class I2 , class Cmp = Std::compare_three_way>
constexpr auto	lexicographical_compare_three_way (I1 f1, I1 l1, I2 f2, I2 l2, Cmp comp={}) -> decltype(comp(*f1, *f2))
	Lexicographically compares two ranges [first1, last1) and [first2, last2) using three-way comparison and produces a result of the strongest applicable comparison category type. More...
template<class T >
constexpr auto	to_address (T &&p) noexcept
	Obtain the address represented by p without forming a reference to the object pointed to by p.

Variables
constexpr std::size_t	dynamic_extent = std::numeric_limits<std::size_t>::max()
	A constant of type std::size_t that is used to differentiate std::span of static and dynamic extent.

Detailed Description

Namespace for features backported from new C++ standards.

The namespace Dune::Std contains library features of new C++ standards and technical specifications backported to older compilers. Most features are detected and pulled into this namespace from the standard library if your compiler has native support. If it doesn't, we provide a fallback implementation on a best-effort basis.

Function Documentation

lexicographical_compare_three_way()

template<class I1 , class I2 , class Cmp = Std::compare_three_way>

constexpr auto Dune::Std::lexicographical_compare_three_way ( I1  f1, I1  l1, I2  f2, I2  l2, Cmp  comp = {}  ) -> decltype(comp(*f1, *f2))

constexpr

Lexicographically compares two ranges [first1, last1) and [first2, last2) using three-way comparison and produces a result of the strongest applicable comparison category type.

Implementation taken from https://en.cppreference.com/w/cpp/algorithm/lexicographical_compare_three_way

The standard implementation is available with libstdc++ >= 10 and libc++ >= 17