Danny Robson
60a7670326
this will allow us to reduce code duplication for sanity checks at construction time.
322 lines
10 KiB
C++
322 lines
10 KiB
C++
/*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* Copyright 2015-2017 Danny Robson <danny@nerdcruft.net>
|
|
*/
|
|
|
|
|
|
#ifndef CRUFT_UTIL_VIEW_HPP
|
|
#define CRUFT_UTIL_VIEW_HPP
|
|
|
|
#include "cast.hpp"
|
|
#include "debug.hpp"
|
|
#include "types/traits.hpp"
|
|
|
|
#include <cstdlib>
|
|
#include <ostream>
|
|
#include <string>
|
|
#include <cstring>
|
|
#include <stdexcept>
|
|
|
|
namespace util {
|
|
template <typename IteratorT>
|
|
struct view {
|
|
public:
|
|
//---------------------------------------------------------------------
|
|
using value_type = typename std::iterator_traits<
|
|
remove_restrict_t<IteratorT>
|
|
>::value_type;
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr
|
|
view (const IteratorT &first, const IteratorT &last) noexcept:
|
|
m_begin (first),
|
|
m_end (last)
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr
|
|
view (const view &rhs) noexcept:
|
|
view (rhs.m_begin, rhs.m_end)
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
// technically we could get away without explicitly defining a move
|
|
// constructor here, but by nulling rhs we can more easily use this
|
|
// class as a base for unique owning pointers without exposing
|
|
// begin/end to them directly.
|
|
constexpr view (view &&rhs) noexcept:
|
|
view (std::move (rhs.m_begin), std::move (rhs.m_end))
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
constexpr explicit
|
|
view (ContainerT &klass):
|
|
view (std::begin (klass), std::end (klass))
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
constexpr explicit
|
|
view (const ContainerT &klass):
|
|
view (std::begin (klass), std::end (klass))
|
|
{ ; }
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
view&
|
|
operator= (const view &rhs) noexcept
|
|
{
|
|
m_begin = rhs.m_begin;
|
|
m_end = rhs.m_end;
|
|
return *this;
|
|
}
|
|
|
|
|
|
//---------------------------------------------------------------------
|
|
view&
|
|
operator= (view &&rhs) noexcept
|
|
{
|
|
m_begin = rhs.m_begin;
|
|
m_end = rhs.m_end;
|
|
|
|
rhs.m_begin = IteratorT{};
|
|
rhs.m_end = IteratorT{};
|
|
|
|
return *this;
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////
|
|
constexpr IteratorT begin (void) noexcept { return m_begin; }
|
|
constexpr IteratorT end (void) noexcept { return m_end; }
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr const IteratorT begin (void) const noexcept { return cbegin (); }
|
|
constexpr const IteratorT end (void) const noexcept { return cend (); }
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr const IteratorT cbegin (void) const noexcept { return m_begin; }
|
|
constexpr const IteratorT cend (void) const noexcept { return m_end; }
|
|
|
|
//---------------------------------------------------------------------
|
|
auto data (void) { return begin (); }
|
|
auto data (void) const { return begin (); }
|
|
|
|
///////////////////////////////////////////////////////////////////////
|
|
constexpr bool
|
|
empty (void) const noexcept
|
|
{
|
|
return m_begin == m_end;
|
|
}
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr auto
|
|
size (void) const noexcept
|
|
{
|
|
return sign_cast<std::size_t> (std::distance (m_begin, m_end));
|
|
}
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr auto
|
|
redim (int count) const
|
|
{
|
|
CHECK_GT (count, 0);
|
|
if (count > size ())
|
|
throw std::invalid_argument ("redim to higher size not allowed");
|
|
return view { m_begin, m_begin + count };
|
|
};
|
|
|
|
///////////////////////////////////////////////////////////////////////
|
|
constexpr value_type&
|
|
operator[] (size_t idx)& noexcept
|
|
{
|
|
auto it = begin ();
|
|
std::advance (it, idx);
|
|
return *it;
|
|
}
|
|
|
|
//---------------------------------------------------------------------
|
|
constexpr const value_type&
|
|
operator[] (size_t idx) const& noexcept
|
|
{
|
|
auto it = begin ();
|
|
std::advance (it, idx);
|
|
return *it;
|
|
}
|
|
|
|
private:
|
|
///////////////////////////////////////////////////////////////////////
|
|
IteratorT m_begin;
|
|
IteratorT m_end;
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename ValueT, size_t N>
|
|
auto
|
|
make_view (const ValueT (&arr)[N])
|
|
{
|
|
return util::view<const ValueT*> (arr + 0, arr + N);
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
auto
|
|
make_view (ContainerT &t)
|
|
{
|
|
return util::view<decltype(std::begin (t))> { std::begin (t), std::end (t) };
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ContainerT>
|
|
auto
|
|
make_view (const ContainerT &t)
|
|
{
|
|
return util::view<decltype(std::cbegin (t))> { std::cbegin (t), std::cend (t) };
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
// disable the possibility of creating a view to a temporary. note that
|
|
// this only works if an lval version has already been defined otherwise
|
|
// universal reference rules will capture both lval and rval here.
|
|
template <typename ContainerT>
|
|
auto
|
|
make_view (ContainerT&&) = delete;
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename ContainerT>
|
|
auto
|
|
make_cview (const ContainerT &t)
|
|
{
|
|
return util::view<decltype(std::cbegin (t))> { std::cbegin (t), std::cend (t) };
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename IteratorT>
|
|
auto
|
|
make_view (IteratorT first, IteratorT last)
|
|
{
|
|
return view<IteratorT> {first, last};
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename ValueT>
|
|
auto
|
|
make_cview (ValueT *first, ValueT *last)
|
|
{
|
|
return view<const ValueT*> {first, last};
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
inline
|
|
view<const char*> make_view (const char *str)
|
|
{
|
|
return { str, str + strlen (str) };
|
|
}
|
|
|
|
//-------------------------------------------------------------------------
|
|
inline
|
|
view<char*> make_view (char *str)
|
|
{
|
|
return { str, str + strlen (str) };
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename CharT, typename TraitsT, typename AllocT>
|
|
view<const CharT*>
|
|
make_view (const std::basic_string<CharT,TraitsT,AllocT> &str)
|
|
{
|
|
return {
|
|
std::data (str),
|
|
std::data (str) + std::size (str)
|
|
};
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename CharT, typename TraitsT, typename AllocT>
|
|
view<CharT*>
|
|
make_view (std::basic_string<CharT,TraitsT,AllocT> &str)
|
|
{
|
|
return {
|
|
std::data (str),
|
|
std::data (str) + std::size (str)
|
|
};
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename CharT, typename TraitsT, typename AllocT>
|
|
view<const CharT*>
|
|
make_view (const std::basic_string<CharT,TraitsT,AllocT>&&) = delete;
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename CharT, typename TraitsT, typename AllocT>
|
|
view<CharT*>
|
|
make_view (std::basic_string<CharT,TraitsT,AllocT>&&) = delete;
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename IteratorT>
|
|
constexpr bool
|
|
operator== (const view<IteratorT> &a, const view<IteratorT> &b)
|
|
{
|
|
return std::cbegin (a) == std::cbegin (b) &&
|
|
std::cend (a) == std::cend (b);
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename IteratorT>
|
|
constexpr bool
|
|
operator!= (const view<IteratorT> &a, const view<IteratorT> &b)
|
|
{
|
|
return !(a == b);
|
|
}
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
// equality operations for string-like views against std::strings
|
|
bool equal (const std::string&, view<const char*>);
|
|
bool equal (const std::string&, view<char*>);
|
|
bool equal (const std::string&, view<std::string::const_iterator>);
|
|
bool equal (const std::string&, view<std::string::iterator>);
|
|
|
|
|
|
bool equal (view<const char*>, const std::string&);
|
|
bool equal (view<char*>, const std::string&);
|
|
bool equal (view<std::string::const_iterator>, const std::string&);
|
|
bool equal (view<std::string::iterator>, const std::string&);
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////
|
|
template <typename IteratorT>
|
|
std::ostream&
|
|
operator<< (std::ostream&, view<IteratorT>);
|
|
}
|
|
|
|
|
|
#endif
|