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VtaAlgo.hpp
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VtaAlgo.hpp
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/******************************************************************//**
* \file algorithms.hpp
* \author Elliot Goodrich
*
* Boost Software License - Version 1.0 - August 17th, 2003
*
* Permission is hereby granted, free of charge, to any person or organization
* obtaining a copy of the software and accompanying documentation covered by
* this license (the "Software") to use, reproduce, display, distribute,
* execute, and transmit the Software, and to prepare derivative works of the
* Software, and to permit third-parties to whom the Software is furnished to
* do so, all subject to the following:
*
* The copyright notices in the Software and this entire statement, including
* the above license grant, this restriction and the following disclaimer,
* must be included in all copies of the Software, in whole or in part, and
* all derivative works of the Software, unless such copies or derivative
* works are solely in the form of machine-executable object code generated by
* a source language processor.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
* SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
* FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*********************************************************************/
#ifndef INCLUDE_GUARD_12E75493_BA12_4EF3_B0D8_92747A030D0E
#define INCLUDE_GUARD_12E75493_BA12_4EF3_B0D8_92747A030D0E
#include <type_traits>
#include <utility>
namespace vta {
// Returns the size of the parameter pack as an integer
template <typename... Args>
constexpr int count(Args&&...) noexcept {
return sizeof...(Args);
}
/**************************************************************************************************
* Macro *
**************************************************************************************************/
// Provided by Florian Weber (http://florianjw.de/en/passing_overloaded_functions.html)
#define VTA_FN_TO_FUNCTOR(...) [](auto&&... args) \
-> decltype(auto){ return __VA_ARGS__(std::forward<decltype(args)>(args)...); }
/**************************************************************************************************
* Predicates *
**************************************************************************************************/
/** are_same */
template <typename... Args>
struct are_same;
template <typename First, typename Second, typename... Args>
struct are_same<First, Second, Args...> {
static bool const value = std::is_same<First, Second>::value
&& are_same<Second, Args...>::value;
};
template <typename Arg>
struct are_same<Arg> : public std::true_type {};
template <>
struct are_same<> : public std::true_type {};
/** are_same_after */
template <template<class> class TypeTransformation, typename... Args>
struct are_same_after {
static bool const value = vta::are_same<typename TypeTransformation<Args>::type...>::value;
};
/** are_unique_ints */
template <int... Ns>
struct are_unique_ints;
template <>
struct are_unique_ints<> {
static bool const value = true;
};
template <int N>
struct are_unique_ints<N> {
static bool const value = true;
};
template <int M, int N, int... Ns>
struct are_unique_ints<M, N, Ns...> {
static bool const value = (M != N)
&& are_unique_ints<M, Ns...>::value
&& are_unique_ints<N, Ns...>::value;
};
/** are_unique */
template <typename... Args>
struct are_unique;
template <>
struct are_unique<> {
static bool const value = true;
};
template <typename Arg>
struct are_unique<Arg> {
static bool const value = true;
};
template <typename Arg1, typename Arg2, typename... Args>
struct are_unique<Arg1, Arg2, Args...> {
static bool const value = (!std::is_same<Arg1, Arg2>::value)
&& are_unique<Arg1, Args...>::value
&& are_unique<Arg2, Args...>::value;
};
/** are_unique_after */
template <template<class> class TypeTransformation, typename... Args>
struct are_unique_after {
static bool const value = vta::are_unique<typename TypeTransformation<Args>::type...>::value;
};
// Forward after
template <typename Function, typename Transformation>
class forward_after_f {
Function mF;
public:
constexpr forward_after_f(Function f)
: mF(std::move(f)) {
}
template <typename... Args>
constexpr auto operator()(Args&&... args) const {
return Transformation::transform(mF, std::forward<Args>(args)...);
}
template <typename... Args>
auto operator()(Args&&... args) {
return Transformation::transform(mF, std::forward<Args>(args)...);
}
};
template <typename Transformation, typename Function>
constexpr forward_after_f<Function, Transformation> forward_after(Function&& f) {
return {std::forward<Function>(f)};
}
/**************************************************************************************************
* Transformations *
**************************************************************************************************/
namespace detail {
template <typename Function, typename... Transforms>
class compose_helper_f;
template <typename Function, typename FirstTransform, typename... Transforms>
class compose_helper_f<Function, FirstTransform, Transforms...> {
Function mF;
public:
constexpr compose_helper_f(Function f)
: mF(std::move(f)) {
}
template <typename... Args>
constexpr auto operator()(Args&&... args) const {
return FirstTransform::transform(compose_helper_f<Function, Transforms...>{mF},
std::forward<Args>(args)...);
}
template <typename... Args>
auto operator()(Args&&... args) {
return FirstTransform::transform(compose_helper_f<Function, Transforms...>{mF},
std::forward<Args>(args)...);
}
};
template <typename Function>
class compose_helper_f<Function> {
Function mF;
public:
compose_helper_f(Function f)
: mF(std::move(f)) {
}
template <typename... Args>
constexpr auto operator()(Args&&... args) const {
return mF(std::forward<Args>(args)...);
}
template <typename... Args>
auto operator()(Args&&... args) {
return mF(std::forward<Args>(args)...);
}
};
}
/** Composes a sequence of transformations. */
template <typename... Transforms>
struct compose {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
typedef detail::compose_helper_f<typename std::remove_reference<Function>::type, Transforms...> Helper;
return Helper{f}(std::forward<Args>(args)...);
}
};
/** Forwards the arguments to f without change. */
struct id {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return std::forward<Function>(f)(std::forward<Args>(args)...);
}
};
/** Calls the function with the given arguments if Condition is true. */
template <bool Condition>
struct call_if;
template <>
struct call_if<true> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <>
struct call_if<false> {
template <typename Function, typename... Args>
constexpr static void transform(Function&&, Args&&...) noexcept {
}
};
/** Flips the first two variables. */
struct flip {
template <typename Function, typename First, typename Second, typename... Args>
constexpr static auto transform(Function&& f, First&& first, Second&& second, Args&&... rest) {
return std::forward<Function>(f)(std::forward<Second>(second),
std::forward<First>(first),
std::forward<Args>(rest)...);
}
};
/** Left cyclic shifts the parameters \a n places. */
template <unsigned N>
struct left_shift {
template <typename Function, typename First, typename... Args>
constexpr static auto transform(Function&& f, First&& first, Args&&... rest) {
static_assert(N < 1 + sizeof...(rest),
"Cannot left shift more than the size of the parameter pack");
return left_shift<N - 1>::transform(std::forward<Function>(f),
std::forward<Args>(rest)...,
std::forward<First>(first));
}
};
template <>
struct left_shift<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... rest) {
return id::transform(std::forward<Function>(f), std::forward<Args>(rest)...);
}
};
/** Right cyclic shifts the parameters \a n places. */
template <unsigned N>
struct right_shift {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(N < sizeof...(args),
"Cannot right shift more than the size of the parameter pack");
return left_shift<sizeof...(Args) - N>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
template <>
struct right_shift<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... rest) {
return id::transform(std::forward<Function>(f), std::forward<Args>(rest)...);
}
};
template <int N, bool NotNegative = (N >= 0)>
struct shift;
template <int N>
struct shift<N, true> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return left_shift<N>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
template <int N>
struct shift<N, false> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return right_shift<-N>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
/** Left cyclic shifts the tail of the parameters \a n places. */
template <unsigned N>
struct left_shift_tail {
template <typename Function, typename Fixed, typename First, typename... Args>
constexpr static auto transform(Function&& f, Fixed&& fixed, First&& first, Args&&... rest) {
static_assert(N < 1 + sizeof...(rest),
"Cannot left shift more than the size of the tail of the parameter pack");
return left_shift_tail<N - 1>::transform(std::forward<Function>(f),
std::forward<Fixed>(fixed),
std::forward<Args>(rest)...,
std::forward<First>(first));
}
};
template <>
struct left_shift_tail<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... rest) {
return id::transform(std::forward<Function>(f), std::forward<Args>(rest)...);
}
};
/** Right cyclic shifts the tail of the parameters \a n places. */
template <unsigned N>
struct right_shift_tail {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(N < sizeof...(args) - 1,
"Cannot right shift more than the size of the tail of the parameter pack");
return left_shift_tail<sizeof...(Args) - N - 1>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
template <>
struct right_shift_tail<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... rest) {
return id::transform(std::forward<Function>(f), std::forward<Args>(rest)...);
}
};
template <int N, bool NotNegative = (N >= 0)>
struct shift_tail;
template <int N>
struct shift_tail<N, true> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return left_shift_tail<N>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
template <int N>
struct shift_tail<N, false> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return right_shift_tail<-N>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
namespace detail {
template <unsigned N>
struct drop_helper {
template <typename Function, typename First, typename... Args>
constexpr static auto transform(Function&& f, First&&, Args&&... args) {
return drop_helper<N - 1>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <>
struct drop_helper<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
}
/** Drops the first N arguments. */
template <int N>
struct drop {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(-count(args...) <= N && N <= count(args...),
"Cannot drop more variables than are passed");
return detail::drop_helper<N < 0 ? N + count(args...) : N>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
namespace detail {
template <unsigned N, bool ForwardAll>
struct take_helper;
template <unsigned N>
struct take_helper<N, true> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <unsigned N>
struct take_helper<N, false> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return compose<left_shift<N>,
drop<sizeof...(args) - N>
>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
}
/** Passes only the first N arguments. */
template <int N>
struct take {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(-count(args...) <= N && N <= count(args...), "Cannot take more parameters that are available");
return detail::take_helper<N < 0 ? N + count(args...) : N,
N == sizeof...(args)>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
template <>
struct take<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&...) {
return std::forward<Function>(f)();
}
};
/** Take only the arguments at positions N, N + 1, ..., M - 1, M */
template <int N, int M>
struct slice {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(-count(args...) <= N && N < count(args...),
"N is out of bounds");
static_assert(-count(args...) <= M && M < count(args...),
"M is out of bounds");
static int const A = (N + count(args...)) % count(args...);
static int const B = (M + count(args...)) % count(args...);
static_assert(A <= B, "N must be <= M");
static_assert(B <= count(args...), "M is out of bounds");
return m_slice<A, B>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
private:
template <unsigned A, unsigned B>
struct m_slice {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return compose<left_shift<A>,
drop<sizeof...(args) - (B - A)>
>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
};
/** Swap the parameters in the positions \a n and \a m. If a number is negative, it is counted from
the end of the parameter pack. e.g. -1 would be the last parameter. */
template <int N, int M>
struct swap {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static int const size = count(args...);
static_assert(-size <= N && N < size,
"N is out of bounds");
static_assert(-size <= M && M < size,
"M is out of bounds");
static int const A = (N + size) % size;
static int const B = (M + size) % size;
static int const min = A < B ? A : B;
static int const max = A < B ? B : A;
return swap_helper<min, max>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
private:
template <int Min, int Max>
struct swap_helper {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return compose<shift<Min>,
shift_tail<Max - Min - 1>,
flip,
shift_tail<-(Max - Min - 1)>,
shift<-Min>
>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <int MinMax>
struct swap_helper<MinMax, MinMax> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
};
namespace detail {
template <int N, int Modulus>
struct modulus {
static int const value = (N + Modulus) % Modulus;
};
}
template <int... Positions>
struct cycle;
template <>
struct cycle<> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <int First>
struct cycle<First> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
template <int First, int Second, int... Rest>
struct cycle<First, Second, Rest...> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
static_assert(vta::are_unique_ints<detail::modulus<First, count(args...)>::value,
detail::modulus<Second, count(args...)>::value,
detail::modulus<Rest, count(args...)>::value...>::value,
"The positions to permute must be unique");
return compose<swap<First, Second>, cycle<First, Rest...>>::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
namespace detail {
template <unsigned N>
struct reverse_helper {
template <typename Function>
constexpr static auto transform(Function&&) {
}
template <typename Function, typename Arg>
constexpr static auto transform(Function&& f, Arg&& arg) {
return id::transform(std::forward<Function>(f), std::forward<Arg>(arg));
}
template <typename Function, typename First, typename... Args>
constexpr static auto transform(Function&& f, First&& first, Args&&... args) {
return compose<swap<N - 1, -N>,
reverse_helper<N - 1>
>::transform(std::forward<Function>(f),
std::forward<First>(first),
std::forward<Args>(args)...);
}
};
template <>
struct reverse_helper<0u> {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return id::transform(std::forward<Function>(f), std::forward<Args>(args)...);
}
};
}
/** Reverse the order of arguments */
struct reverse {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
return detail::reverse_helper<sizeof...(args) / 2>::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
namespace detail {
template <template <class> class Predicate, typename... Passed>
struct filter_helper;
template <template <class> class Predicate, bool Passed, typename... Passed>
struct next_has_passed;
template <template <class> class Predicate, typename... Passed>
struct next_has_passed<Predicate, true, Passed...> {
template <typename Function, typename Next, typename... ToBeEvaluated>
constexpr static auto transform(Function&& f, Passed&&... passed, Next&& next, ToBeEvaluated&&... rest) {
return filter_helper<Predicate, Passed..., Next>::transform(std::forward<Function>(f),
std::forward<Passed>(passed)...,
std::forward<Next>(next),
std::forward<ToBeEvaluated>(rest)...);
}
template <typename Function>
constexpr static auto transform(Function&& f, Passed&&... passed) {
return std::forward<Function>(f)(std::forward<Passed>(passed)...);
}
};
template <template <class> class Predicate, typename... Passed>
struct next_has_passed<Predicate, false, Passed...> {
template <typename Function, typename Next, typename... ToBeEvaluated>
constexpr static auto transform(Function&& f, Passed&&... passed, Next&&, ToBeEvaluated&&... rest) {
return filter_helper<Predicate, Passed...>::transform(std::forward<Function>(f),
std::forward<Passed>(passed)...,
std::forward<ToBeEvaluated>(rest)...);
}
template <typename Function>
constexpr static auto transform(Function&& f, Passed&&... passed) {
return std::forward<Function>(f)(std::forward<Passed>(passed)...);
}
};
template <template <class> class Predicate, typename... Passed>
struct filter_helper {
template <typename Function, typename Next, typename... ToBeEvaluated>
constexpr static auto transform(Function&& f, Passed&&... passed, Next&& next, ToBeEvaluated&&... rest) {
typedef next_has_passed<Predicate,
Predicate<Next>::value,
Passed...> NextTransform;
return NextTransform::transform(std::forward<Function>(f),
std::forward<Passed>(passed)...,
std::forward<Next>(next),
std::forward<ToBeEvaluated>(rest)...);
}
template <typename Function, typename... ToBeEvaluated>
constexpr static auto transform(Function&& f, Passed&&... passed) {
return std::forward<Function>(f)(std::forward<Passed>(passed)...);
}
};
}
/** Filter in parameters only if Predicate<Arg>::value is true for each argument type. */
template <template <class> class Predicate>
struct filter {
template <typename Function, typename... Args>
constexpr static auto transform(Function&& f, Args&&... args) {
typedef detail::filter_helper<Predicate> Next;
return Next::transform(std::forward<Function>(f),
std::forward<Args>(args)...);
}
};
/**************************************************************************************************
* Functions *
**************************************************************************************************/
template <typename Function>
class map_f {
Function mF;
public:
constexpr map_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename... Args>
constexpr void operator()(First&& first, Args&&... args) const {
mF(std::forward<First>(first));
operator()(std::forward<Args>(args)...);
}
template <typename First, typename... Args>
void operator()(First&& first, Args&&... args) {
mF(std::forward<First>(first));
operator()(std::forward<Args>(args)...);
}
constexpr void operator()() const {
}
};
template <typename Function>
constexpr map_f<typename std::remove_reference<Function>::type> map(Function&& f) {
return {std::forward<Function>(f)};
}
template <unsigned N, typename Function>
class adjacent_map_f {
Function mF;
public:
constexpr adjacent_map_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename... Args>
void operator()(First&& first, Args&&... args) const {
take<N>::transform(mF, std::forward<First>(first), args...);
call_if<(sizeof...(args) >= N)>::transform(*this, std::forward<Args>(args)...);
}
template <typename First, typename... Args>
void operator()(First&& first, Args&&... args) {
take<N>::transform(mF, std::forward<First>(first), args...);
call_if<(sizeof...(args) >= N)>::transform(*this, std::forward<Args>(args)...);
}
};
template <unsigned N, typename Function>
constexpr adjacent_map_f<N, typename std::remove_reference<Function>::type> adjacent_map(Function&& f) {
return {std::forward<Function>(f)};
}
template <typename Function>
class foldl_f {
Function mF;
public:
constexpr foldl_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename Second, typename... Args>
constexpr auto operator()(First&& first, Second&& second, Args&&... args) const {
return (*this)(mF(std::forward<First>(first), std::forward<Second>(second)),
std::forward<Args>(args)...);
}
template <typename First, typename Second, typename... Args>
auto operator()(First&& first, Second&& second, Args&&... args) {
return (*this)(mF(std::forward<First>(first), std::forward<Second>(second)),
std::forward<Args>(args)...);
}
private:
template <typename Arg>
constexpr Arg operator()(Arg&& arg) const {
return std::forward<Arg>(arg);
}
};
template <typename Function>
constexpr foldl_f<typename std::remove_reference<Function>::type> foldl(Function&& f) {
return {std::forward<Function>(f)};
}
template <typename Function>
class foldr_f {
Function mF;
public:
foldr_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename Second, typename... Args>
constexpr auto operator()(First&& first, Second&& second, Args&&... args) const {
return mF(std::forward<First>(first),
(*this)(std::forward<Second>(second), std::forward<Args>(args)...));
}
template <typename First, typename Second, typename... Args>
auto operator()(First&& first, Second&& second, Args&&... args) {
return mF(std::forward<First>(first),
(*this)(std::forward<Second>(second), std::forward<Args>(args)...));
}
template <typename Arg>
constexpr Arg operator()(Arg&& arg) const noexcept {
return std::forward<Arg>(arg);
}
};
template <typename Function>
constexpr foldr_f<typename std::remove_reference<Function>::type> foldr(Function&& f) {
return {std::forward<Function>(f)};
}
template <typename Function>
class all_of_f {
Function mF;
public:
constexpr all_of_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename... Args>
constexpr bool operator()(First&& first, Args&&... args) const {
return mF(std::forward<First>(first)) ? operator()(std::forward<Args>(args)...) : false;
}
template <typename First, typename... Args>
bool operator()(First&& first, Args&&... args) {
return mF(std::forward<First>(first)) ? operator()(std::forward<Args>(args)...) : false;
}
constexpr bool operator()() const {
return true;
}
};
template <typename Function>
constexpr all_of_f<typename std::remove_reference<Function>::type> all_of(Function&& f) {
return {std::forward<Function>(f)};
}
template <typename Function>
class any_of_f {
Function mF;
public:
constexpr any_of_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename... Args>
constexpr bool operator()(First&& first, Args&&... args) const {
return mF(std::forward<First>(first)) ? true : operator()(std::forward<Args>(args)...);
}
template <typename First, typename... Args>
bool operator()(First&& first, Args&&... args) {
return mF(std::forward<First>(first)) ? true : operator()(std::forward<Args>(args)...);
}
constexpr bool operator()() const {
return false;
}
};
template <typename Function>
constexpr any_of_f<typename std::remove_reference<Function>::type> any_of(Function&& f) {
return {std::forward<Function>(f)};
}
template <typename Function>
class none_of_f {
Function mF;
public:
constexpr none_of_f(Function f)
: mF(std::move(f)) {
}
template <typename First, typename... Args>
constexpr bool operator()(First&& first, Args&&... args) const {
return mF(std::forward<First>(first)) ? false : operator()(std::forward<Args>(args)...);
}
template <typename First, typename... Args>
bool operator()(First&& first, Args&&... args) {
return mF(std::forward<First>(first)) ? false : operator()(std::forward<Args>(args)...);
}
constexpr bool operator()() const noexcept {
return true;
}
};
template <typename Function>
constexpr none_of_f<typename std::remove_reference<Function>::type> none_of(Function&& f) {
return {std::forward<Function>(f)};
}
/**************************************************************************************************
* Utility Functions *
**************************************************************************************************/
template <typename T>
constexpr T const& add_const(T&& t) noexcept {
return t;
}
template <typename Arg, typename... Args>
constexpr auto head(Arg&& head, Args&&...) noexcept {
return std::forward<Arg>(head);
}
template <typename Arg>
constexpr auto last(Arg&& arg) noexcept {
return std::forward<Arg>(arg);
}
template <typename Arg1, typename... Args>
constexpr auto last(Arg1&&, Args&&... rest) noexcept {
return last(std::forward<Args>(rest)...);
}
namespace detail {
template <unsigned N>
struct at_helper;
template <unsigned N>
struct at_helper {
template <typename Arg, typename... Args>
constexpr static auto get(Arg&&, Args&&... args) noexcept {
return at_helper<N - 1>::get(std::forward<Args>(args)...);
}
};
template <>
struct at_helper<0u> {
template <typename... Args>
constexpr static auto get(Args&&... args) noexcept {
return head(std::forward<Args>(args)...);
}
};
}
template <int N, typename... Args>
constexpr auto at(Args&&... args) noexcept {
static_assert(-count(args...) <= N && N < count(args...), "N is out of bounds");
return detail::at_helper<(N + count(args...)) % count(args...)>::get(std::forward<Args>(args)...);
}
/**************************************************************************************************
* Type Aliases *
**************************************************************************************************/
template <typename... Args>
using head_t = decltype(head(std::declval<Args>()...));
template <typename... Args>
using last_t = decltype(last(std::declval<Args>()...));
template <int N>
struct at_t {
template <typename... Args>
using type = decltype(at<N>(std::declval<Args>()...));
};
}
#endif