cxxomfort::fix Namespace Reference

Fixes for implementation issues in std. More...

Classes
struct	integral_limits
	An extension to numeric_limits that deals specifically with integer-like types. More...
struct	is_contiguous_access_iterator
	Tags an iterator as a contiguous access type iterator. More...
struct	malloc_deleter
	Deleter operator that uses free() for malloc-reserved blocks. More...
struct	shuffle_order_engine
	Forwarder for std::shuffle_order_engine. More...

Typedefs
typedef shuffle_order_engine< minstd_rand, 256 >	knuth_b
	Forwarder for the std::knuth_b specialization of shuffle_order_engine .See shuffle_order_engine above.

Functions
template<typename T >
constexpr T	clamp (cxxomfort::constexpr_t, T x, T Min, T Max) noexcept
template<typename It , typename T >
constexpr It	find (cxxomfort::constexpr_t const, It ini, It fin, T const &value)
template<typename It , typename Fn >
constexpr It	find_if (cxxomfort::constexpr_t const, It ini, It fin, Fn &&fn)
template<typename It , typename T >
constexpr size_t	count (cxxomfort::constexpr_t const, It ini, It fin, T const &value) noexcept
template<typename It , typename Fn >
constexpr size_t	count_if (cxxomfort::constexpr_t const, It ini, It fin, Fn &&fn) noexcept
template<typename Integral >
constexpr std::byte	to_byte (Integral i) noexcept
	Constructs a std::byte using an integral value. More...
template<typename T >
auto	cdata (C const &container) -> decltype(container.data())
	Returns container.data() as a const-pointer for a given container. More...
template<typename It , typename = typename std::enable_if<std::is_pointer<It>::value, bool>>
constexpr It	static_next (It const p) noexcept
	Given a compile-time const (or constexpr ) iterator, returns the iterator to the next position.
template<typename It , typename = typename std::enable_if<std::is_pointer<It>::value, bool>>
constexpr It	static_prev (It const p) noexcept
	Given a compile-time const (or constexpr ) iterator, returns the iterator to the previous position. More...
template<typename T >
bool	to_bool (std::shared_ptr< T > const &p) noexcept
template<typename T >
bool	to_bool (std::unique_ptr< T > const &p) noexcept
template<class Ty , Ty u>
CXXO_CONSTEXPR Ty	to_integer (std::integral_constant< Ty, u > const) CXXO_NOEXCEPTNOTHROW
	Returns the value corresponding to a integral_constant.-utils Recovers the value corresponding to a integral_constant. More...
template<class Ty , Ty u>
CXXO_CONSTEXPR Ty	to_value (std::integral_constant< Ty, u > const) CXXO_NOEXCEPTNOTHROW
	Returns the value corresponding to a integral_constant. More...

Detailed Description

Fixes for implementation issues in std.

Namespace that holds fixes and alternative implementations or names for stuff in C++ std that can not be modified or reimplemented.

See "Implementation Fixes" for more details.

---

Class Documentation

cxxomfort::fix::integral_limits

struct cxxomfort::fix::integral_limits

template<typename T>
struct cxxomfort::fix::integral_limits< T >

An extension to numeric_limits that deals specifically with integer-like types.

Compile-time constants for integral limits

For a given integral or integer-like type Ty , integral_limits<Ty> provides an interface to std::numeric_limits<Ty> and in fact inherits from the latter. The interface is expanded to add some useful information about the integral type that is only available at compile time as macros pre-C++11.

integral_limits provides the following new members:

• const_min - minimum value as a value (min is constexpr function in C++>=11).
• const_max - maximum value as a value (max is constexpr function in C++>=11).
• digits_base<N> - the total number of digits required to represent any value in the given base.

Pending members :

• narrower_type - an alias to the next smaller integral type of the same signedness.
• wider_type - an alias to the next larger integral type of the same signedness.
• lo_mask - an integral value that can be AND-ed with this type to keep only the lower bits.
• hi_mask - an integral value that can be AND-ed with this type to keep only the higher bits.

cxxomfort provides specializations of the new integral_limits for all the types that are defined as integral. The list explicitly includes:

short, int, long, long long in their signed and unsigned variants.

cxxomfort::fix::is_contiguous_access_iterator

struct cxxomfort::fix::is_contiguous_access_iterator

template<typename Iterator, typename Tag = typename std::iterator_traits<Iterator>::iterator_category>
struct cxxomfort::fix::is_contiguous_access_iterator< Iterator, Tag >

Tags an iterator as a contiguous access type iterator.

Given an iterator type I, indicates whether the type either:

• matches the contiguous_iterator_tag tag
• or represents access to a contiguous area of memory, like an array

Pre C++17, this can only be implemented as an heuristic and can not determine contiguousness of storage types where the iterator is being wrapped, in which cases it will always declare false .

One such example is <array> and <vector> iterators in MSVC, in versions that don't support disabling the debug iterator mode.

cxxomfort::fix::shuffle_order_engine

struct cxxomfort::fix::shuffle_order_engine

template<typename Engine, unsigned K>
struct cxxomfort::fix::shuffle_order_engine< Engine, K >

Forwarder for std::shuffle_order_engine.

<random>:

Forwarder.

Some compilers, such as MSVC 2008, 2010, don't implement shuffle_order_engine , and some other compilers don't implement it at all. This name will redirect to cxxomfort's implementation in those cases, or to std::shuffle_order_engine otherwise.

Function Documentation

clamp()

constexpr T cxxomfort::fix::clamp ( cxxomfort::constexpr_t  , T  x, T  Min, T  Max  )

inlinenoexcept

Implementation of std::clamp with constexpr

Referenced by cxxomfort::library::algorithm::is_clamped().

find()

constexpr It cxxomfort::fix::find	(	cxxomfort::constexpr_t	const,
		It	ini,
		It	fin,
		T const &	value
	)

C++20 Backports:

Adding constexpr capability to std::find()

Adds an "overload" to std::find() so that pre-C++20 can invoke it in constexpr in contexts where the compiler makes it possible.

using cxxomfort::fix::find;
constexpr int Data[N] = { ...};
constexpr int const* p = find( cxxomfort::constexpr_tag, Data, Data+N, 9);

Note

This is defined only starting with C++11.

Referenced by basic_string_view< Ch, ChT >::find(), find_if(), and cxxomfort::cxxostd::is_permutation().

find_if()

constexpr It cxxomfort::fix::find_if	(	cxxomfort::constexpr_t	const,
		It	ini,
		It	fin,
		Fn &&	fn
	)

C++20 Backports:

Adding constexpr capability to std::find_if()

Adds an "overload" to std::find_if() so that pre-C++20 can invoke it in constexpr in contexts where the compiler makes it possible.

Note

This is defined only starting with C++11.

count()

constexpr size_t cxxomfort::fix::count ( cxxomfort::constexpr_t  const, It  ini, It  fin, T const &  value  )

noexcept

C++20 Backports:

Adding constexpr capability to std::count()

Adds an "overload" to std::count() so that pre-C++20 can invoke it in constexpr in contexts where the compiler makes it possible.

using cxxomfort::fix::count;
constexpr int Data[N] = { ...};
constexpr int const* p = count( cxxomfort::constexpr_tag, Data, Data+N, 9);

Note

This is defined only starting with C++11.

count_if()

constexpr size_t cxxomfort::fix::count_if ( cxxomfort::constexpr_t  const, It  ini, It  fin, Fn &&  fn  )

noexcept

C++20 Backports:

Adding constexpr capability to std::count_if()

Adds an "overload" to std::count_if() so that pre-C++20 can invoke it in constexpr in contexts where the compiler makes it possible.

Note

This is defined only starting with C++11.

to_byte()

constexpr std::byte cxxomfort::fix::to_byte ( Integral  i )

noexcept

Constructs a std::byte using an integral value.

Precondition

Integral is a C++ integral type.

Converts an integral value to byte .Create byte values.

Referenced by to_byte().

cdata()

auto cxxomfort::fix::cdata

(

C const &

container

)

-> decltype(container.data())

Returns container.data() as a const-pointer for a given container.

Parameters

container

A container or expression representing one.

Returns

An iterator of the type of container.data(); pre-C++11, a Container::const_pointer .

Precondition

The argument implements the .data() member with the required semantics (contiguous storage).

cdata()

static_prev()

constexpr It cxxomfort::fix::static_prev ( It const  p )

noexcept

Given a compile-time const (or constexpr ) iterator, returns the iterator to the previous position.

static_prev

to_bool() [1/2]

bool cxxomfort::fix::to_bool ( std::shared_ptr< T > const &  p )

inlinenoexcept

Returns true if the shared_ptr currently hosts a value.

Referenced by to_value().

to_bool() [2/2]

bool cxxomfort::fix::to_bool ( std::unique_ptr< T > const &  p )

inlinenoexcept

Returns true if the unique_ptr currently hosts a value.

to_integer()

CXXO_CONSTEXPR Ty cxxomfort::fix::to_integer ( std::integral_constant< Ty, u >  const )

inline

Returns the value corresponding to a integral_constant.-utils Recovers the value corresponding to a integral_constant.

This function is a helper for versions of C++ pre-C++14 which introduced the integral_constant conversion operator and function call.

See also

types/integral_constant @ cppreference

to_value()

CXXO_CONSTEXPR Ty cxxomfort::fix::to_value ( std::integral_constant< Ty, u >  const )

inline

Returns the value corresponding to a integral_constant.

Value corresponding to a integral_constant.

This function is a helper for versions of C++ pre-C++14 which introduced the integral_constant conversion operator and function call.

See also

types/integral_constant @ cppreference