cxxomfort Supplementals for <algorithm> More...

Namespaces
	cxxomfort
	Namespace of the `cxxomfort` library.

	cxxomfort::library
	Supplements to backports and other utilities.

Functions
template<typename Container >
void	erase (Container &C, typename Container::value_type const &u)
	Invokes erase-remove idiom on a container to remove element u as per `remove()` . More...

template<typename Container , typename Pred >
void	erase_if (Container &C, Pred if_)
	Invokes erase-remove idiom on a container to remove elements conditionally given predicate if_ as per `remove_if()` . More...

template<typename T , typename Compare >
CXXO_CONSTEXPR bool	is_clamped (T const &value, T const &lo, T const &hi, Compare less) CXXO_NOEXCEPTNOTHROW
	Checks if a value is clamped. More...

template<typename T >
CXXO_CONSTEXPR bool	is_clamped (T const &value, T const &lo, T const &hi) CXXO_NOEXCEPTNOTHROW

template<class T , class Compare >
CXXO_CONSTEXPR T const &	clamp_halfopen (T const &val, T const &lo, T const &hi, Compare less) CXXO_NOEXCEPT
	Clamps a value within a half-open range. More...

template<class T >
CXXO_CONSTEXPR T const &	clamp_halfopen (T const &val, T const &lo, T const &hi) CXXO_NOEXCEPT

template<typename T , typename Compare >
CXXO_CONSTEXPR bool	is_clamped_halfopen (T const &value, T const &lo, T const &hi, Compare less) CXXO_NOEXCEPTNOTHROW
	Checks if a value is clamped in a half-open interval as per `clamp_halfopen()` More...

template<typename T >
CXXO_CONSTEXPR bool	is_clamped_halfopen (T const &value, T const &lo, T const &hi) CXXO_NOEXCEPTNOTHROW

template<typename OutI , typename InpI , typename Pred >
OutI	copy_if_not (InpI ini, InpI fin, OutI dest, Pred p)
	Copy like `copy_if` with inverted predicate (for symmetry with `find_if_not` ). More...

template<typename Iter1 , typename Integer , typename Iter2 >
Iter2	copy_leftmost_n (Iter1 ini1, Iter1, Integer n, Iter2 ini2)
	Like `copy_n` in that it copies leftmost ("starting") n elements from the sequence. More...

template<typename It1 , typename Integer , typename It2 >
It2	copy_rightmost_n (It1 ini1, It1 fin1, Integer n, It2 ini2)
	Like `copy_n` except it copies the rightmost n elements from the sequence. More...

template<typename It , typename Pred , typename T >
It	find (It ini, It fin, Pred if_, T const &v)
	Finds an element x in a sequence such that `if_(x,v)` holds. More...

template<typename It , typename T >
It	find_not (It ini, It fin, T const &t)
	Finds the first element in the sequence not equal to t . More...

template<typename It , typename Pred >
It	find_if_not (It ini, It fin, Pred if_)
	Finds the first element in the sequence not fitting predicate if_ . More...

template<typename Iter , typename Less >
Iter	find_inversion (Iter ini, Iter fin, Less lt)
	Finds a pair of elements that are out of place (ie.: the second one is "less" than the first). More...

template<typename Iter >
Iter	find_inversion (Iter ini, Iter fin)

template<typename Iter , typename Less >
Iter	fix_inversion (Iter ini, Iter fin, Less m)
	Fixes a pair of misplaced elements where the second one is "less" than the first. More...

template<typename Iter , typename Pred >
Iter	find_last_if (Iter ini, Iter fin, Pred if_)
	Finds the latest item in a sequence that fits predicate `if_` . More...

template<class InputIterator , class UnaryPredicate >
std::iterator_traits< InputIterator >::difference_type	count_while (InputIterator first, InputIterator last, UnaryPredicate pred)

template<typename FIter , typename TF >
FIter	transform_inplace (FIter ini, FIter fin, TF tf)
	Transform elements in the range in-place via the transformation tf . More...

template<typename FIter , typename TF , typename P >
FIter	transform_inplace_if (FIter ini, FIter fin, TF tf, P p)
	Transform elements in the range conditionally. More...

template<typename IIterator , typename OIterator , typename TF , typename Integer >
OIterator	transform_n (IIterator ini, Integer n, OIterator dest, TF tf)
	Transform elements up to n times. More...

template<typename Iterator , typename ValueMapIterator , typename Reductor >
Iterator	count_frequencies_map (Iterator ini, Iterator fin, ValueMapIterator vi, Reductor const rint)
	Constructs a map of frequencies each element appears in the sequence. More...

Detailed Description

cxxomfort Supplementals for <algorithm>

Function Documentation

◆ is_clamped() [1/2]

CXXO_CONSTEXPR bool cxxomfort::library::algorithm::is_clamped	(	T const &	value,
		T const &	lo,
		T const &	hi,
		Compare	less
	)

Checks if a value is clamped.

Parameters

less	A relational predicate with semantics similar to those of `std::less` or `operator<()`

Returns: true if value is within the constraints.

""

See also: {p1440} algorithm/clamp @ cppreference

This is an implementation of p1440 "is_clamped": a complement to clamp() in the same way is_sorted() is a complement to sort().

Given general invocations of clamp(), the following assertion should hold:

(is_clamped(x, lo, hi)) == (x == clamp(x,lo,hi))

Warning: The behaviour is undefined if hi < lo.

Note: Unlike the p1440 proposal, is_clamped() here is marked noexcept ; I consider there is no good scenario where relational comparison operators, or anything that mimics them, would be throwing, and clamp() is to abort rather than throw upon precondition violation.

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

◆ is_clamped() [2/2]

CXXO_CONSTEXPR bool cxxomfort::library::algorithm::is_clamped	(	T const &	value,
		T const &	lo,
		T const &	hi
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ clamp_halfopen() [1/2]

CXXO_CONSTEXPR T const& cxxomfort::library::algorithm::clamp_halfopen	(	T const &	val,
		T const &	lo,
		T const &	hi,
		Compare	less
	)

Clamps a value within a half-open range.

Parameters

less	A relational predicate with semantics similar to those of `std::less` or `operator<()`

Returns: An altered value from val to fit into the half-open interval [lo , hi ).

See also: algorithm/clamp @ cppreference

clamp_halfopen(V,a,b) is similar to clamp(V,a,b) except that b is excluded as a potential resulting value.

Warning: The behaviour is undefined if hi < lo.

Referenced by cxxomfort::library::algorithm::clamp_halfopen(), and cxxomfort::library::algorithm::is_clamped_halfopen().

◆ clamp_halfopen() [2/2]

CXXO_CONSTEXPR T const& cxxomfort::library::algorithm::clamp_halfopen	(	T const &	val,
		T const &	lo,
		T const &	hi
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ is_clamped_halfopen() [1/2]

CXXO_CONSTEXPR bool cxxomfort::library::algorithm::is_clamped_halfopen	(	T const &	value,
		T const &	lo,
		T const &	hi,
		Compare	less
	)

Checks if a value is clamped in a half-open interval as per clamp_halfopen()

Returns: a bool.

This is a supplement to p1440 "is_clamped" in that it checks if the value is clamped in a half-open interval.

Given the general concept of calls to clamp(), the following assertion should hold:

(is_clamped_halfopen(x, lo, hi)) if and only if (x == clamp_halfopen(x,lo,hi))

Warning: The behaviour is undefined if hi < lo.

Note: is_clamped_halfopen() here is marked noexcept ; I consider there is no good scenario where relational comparison operators, or anything that mimics them, would be throwing.

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

◆ is_clamped_halfopen() [2/2]

CXXO_CONSTEXPR bool cxxomfort::library::algorithm::is_clamped_halfopen	(	T const &	value,
		T const &	lo,
		T const &	hi
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ copy_if_not()

OutI cxxomfort::library::algorithm::copy_if_not	(	InpI	ini,
		InpI	fin,
		OutI	dest,
		Pred	p
	)

inline

Copy like copy_if with inverted predicate (for symmetry with find_if_not ).

See also: algorithm/copy_if @ cppreference

This is provided for symmetry with: std::find_if_not(), std::copy_if().

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

◆ copy_leftmost_n()

Iter2 cxxomfort::library::algorithm::copy_leftmost_n	(	Iter1	ini1,
		Iter1	,
		Integer	n,
		Iter2	ini2
	)

Like copy_n in that it copies leftmost ("starting") n elements from the sequence.

This function copies the first n elements from the sequence starting at ini1. While it is basically equivalent to copy_n() , it is provided for symmetry and completeness with copy_rightmost_n() .

See also: algorithm/copy_n @ cppreference; copy_rightmost_n() .

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

◆ copy_rightmost_n()

It2 cxxomfort::library::algorithm::copy_rightmost_n	(	It1	ini1,
		It1	fin1,
		Integer	n,
		It2	ini2
	)

Like copy_n except it copies the rightmost n elements from the sequence.

Returns: Iterator pointing to the end of the copied sequence at the destination.

See also: copy_leftmost_n()

◆ find()

It cxxomfort::library::algorithm::find	(	It	ini,
		It	fin,
		Pred	if_,
		T const &	v
	)

Finds an element x in a sequence such that if_(x,v) holds.

Returns: Iterator pointing to the found element, or fin.

This is taken from proposal wlg217.

◆ find_not()

It cxxomfort::library::algorithm::find_not	(	It	ini,
		It	fin,
		T const &	t
	)

Finds the first element in the sequence not equal to t .

Returns: An iterator, or fin .

See also: find()

This is provided for homology with: std::find, std::find_if_not.

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

◆ find_if_not()

It cxxomfort::library::algorithm::find_if_not	(	It	ini,
		It	fin,
		Pred	if_
	)

Finds the first element in the sequence not fitting predicate if_ .

Returns: An iterator, or fin .

See also: find_if()

◆ find_inversion() [1/2]

Iter cxxomfort::library::algorithm::find_inversion	(	Iter	ini,
		Iter	fin,
		Less	lt
	)

inline

Finds a pair of elements that are out of place (ie.: the second one is "less" than the first).

Returns: Iterator pointing to the first such element, or fin if none.

For example, for the following example find_inversion will return an iterator pointing to the element 6:

vector<int> elems = { -17, 3, 6, -2, -3, -4 };
//                            ^  sorting order is broken in this pair
vector<int>::iterator br = find_inversion( begin(elems), end(elems) );
// at this point, br points to index 2 (element 6).

◆ find_inversion() [2/2]

Iter cxxomfort::library::algorithm::find_inversion	(	Iter	ini,
		Iter	fin
	)

inline

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

◆ fix_inversion()

Iter cxxomfort::library::algorithm::fix_inversion	(	Iter	ini,
		Iter	fin,
		Less	m
	)

inline

Fixes a pair of misplaced elements where the second one is "less" than the first.

Returns: Iterator pointing to the first such element, or fin if none.

◆ find_last_if()

Iter cxxomfort::library::algorithm::find_last_if	(	Iter	ini,
		Iter	fin,
		Pred	if_
	)

Finds the latest item in a sequence that fits predicate if_ .

Parameters

ini,fin	Delimiters to the sequence to be examined.
if_	A predicate (a function from ini...fin's alue type to `bool` ).

Returns: An iterator pointing to the latest item in [ini,fin) that fulfills if_ . This is provided for homology with: std::find_if.

◆ count_while()

std::iterator_traits<InputIterator>::difference_type cxxomfort::library::algorithm::count_while	(	InputIterator	first,
		InputIterator	last,
		UnaryPredicate	pred
	)

count_while proposal https://groups.google.com/a/isocpp.org/forum/?fromgroups#!topic/std-proposals/bXrQrkBw59c

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

◆ transform_inplace()

FIter cxxomfort::library::algorithm::transform_inplace	(	FIter	ini,
		FIter	fin,
		TF	tf
	)

Transform elements in the range in-place via the transformation tf .

Parameters

ini,fin	Iterators marking a writable sequence.
tf	A transformation of the form `TF(value_type) → value_type`.

Returns: The end iterator of the sequence.

""

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

◆ transform_inplace_if()

FIter cxxomfort::library::algorithm::transform_inplace_if	(	FIter	ini,
		FIter	fin,
		TF	tf,
		P	p
	)

Transform elements in the range conditionally.

Parameters

ini,fin	Iterators marking a writable sequence.
tf	A transformation of the form `TF(FIter) -> FIter`.
p	a predicate to decide if the elements need transformation.

Returns: The end iterator of the sequence.

This is provided for homology with: std::copy_if

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

◆ transform_n()

OIterator cxxomfort::library::algorithm::transform_n	(	IIterator	ini,
		Integer	n,
		OIterator	dest,
		TF	tf
	)

inline

Transform elements up to n times.

Parameters

tf	A transformation of the form `TF(FIter) -> FIter`.

This is provided for homology with: std::copy_n.

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

◆ count_frequencies_map()

Iterator cxxomfort::library::algorithm::count_frequencies_map	(	Iterator	ini,
		Iterator	fin,
		ValueMapIterator	vi,
		Reductor const	rint
	)

Constructs a map of frequencies each element appears in the sequence.

Given a sequence S=[ini,fin), and a map vi of elements of type X with an associated mapping function rint such that:

f "rint" : (X) → [0, 1, ..., k]

Then it iterates over S and increments the value at vi+f(x) .

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

◆ erase()

void cxxomfort::library::algorithm::lfv2::erase	(	Container &	C,
		typename Container::value_type const &	u
	)

Invokes erase-remove idiom on a container to remove element u as per remove() .

Parameters

C	a container object (lvalue).
u	the value to pass to `C.remove()` .

Exceptions

exception Whatever the expression C.erase(...) throws.

See also: experimental/lib_extensions_2 @ cppreference

Referenced by cxxomfort::library::algorithm::lfv2::erase().

◆ erase_if()

void cxxomfort::library::algorithm::lfv2::erase_if	(	Container &	C,
		Pred	if_
	)

Invokes erase-remove idiom on a container to remove elements conditionally given predicate if_ as per remove_if() .

Parameters

C	a container object (lvalue).
if_	A predicate to pass to `C.remove_if()` .

Exceptions

exception Whatever the expression C.erase(...) throws.

See also: experimental/lib_extensions_2 @ cppreference

Referenced by cxxomfort::library::algorithm::lfv2::erase_if().

Namespaces

Functions

Detailed Description

Function Documentation

◆ is_clamped() [1/2]

◆ is_clamped() [2/2]

◆ clamp_halfopen() [1/2]

◆ clamp_halfopen() [2/2]

◆ is_clamped_halfopen() [1/2]

◆ is_clamped_halfopen() [2/2]

◆ copy_if_not()

◆ copy_leftmost_n()

◆ copy_rightmost_n()

◆ find()

◆ find_not()

◆ find_if_not()

◆ find_inversion() [1/2]

◆ find_inversion() [2/2]

◆ fix_inversion()

◆ find_last_if()

◆ count_while()

◆ transform_inplace()

◆ transform_inplace_if()

◆ transform_n()

◆ count_frequencies_map()

◆ erase()

◆ erase_if()