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/*
Userspace Virtual Filesystem
Copyright (C) 2015 Sebastian Herbord. All rights reserved.
This file is part of usvfs.
usvfs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
usvfs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with usvfs. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include "exceptionex.h"
namespace usvfs::shared
{
enum class CodePage
{
LOCAL,
LATIN1,
UTF8
};
template <typename ToT, typename FromT>
class string_cast_impl
{
public:
static ToT cast(const FromT& source, CodePage codePage, size_t sourceLength);
};
template <typename ToT, typename FromT>
ToT string_cast(FromT source, CodePage codePage = CodePage::LOCAL,
size_t sourceLength = std::numeric_limits<size_t>::max())
{
return string_cast_impl<ToT, FromT>::cast(source, codePage, sourceLength);
}
template <typename ToT, typename CharT>
class string_cast_impl<ToT, std::basic_string<CharT>>
{
public:
static ToT cast(const std::basic_string<CharT>& source, CodePage codePage,
size_t sourceLength)
{
return string_cast_impl<ToT, const CharT*>::cast(source.c_str(), codePage,
sourceLength);
}
};
template <typename ToT, typename CharT>
class string_cast_impl<ToT, CharT*>
{
BOOST_STATIC_ASSERT(!boost::is_base_and_derived<ToT, CharT>::value);
public:
static ToT cast(CharT* source, CodePage codePage, size_t sourceLength)
{
return string_cast_impl<ToT, const CharT*>::cast(source, codePage, sourceLength);
}
};
template <typename ToT, typename CharT, int N>
class string_cast_impl<ToT, CharT[N]>
{
public:
static ToT cast(CharT (&source)[N], CodePage codePage, size_t sourceLength)
{
return string_cast_impl<ToT, const CharT*>::cast(source, codePage, sourceLength);
}
};
UINT windowsCP(CodePage codePage);
template <>
class string_cast_impl<std::string, const wchar_t*>
{
public:
static std::string cast(const wchar_t* const& source, CodePage codePage,
size_t sourceLength)
{
std::string result;
if (sourceLength == std::numeric_limits<size_t>::max()) {
sourceLength = wcslen(source);
}
if (sourceLength > 0) {
// use utf8 or local 8-bit encoding depending on user choice
UINT cp = windowsCP(codePage);
// preflight to find out the required buffer size
int outLength = WideCharToMultiByte(cp, 0, source, static_cast<int>(sourceLength),
nullptr, 0, nullptr, nullptr);
if (outLength == 0) {
throw windows_error("string conversion failed");
}
result.resize(outLength);
outLength = WideCharToMultiByte(cp, 0, source, static_cast<int>(sourceLength),
&result[0], outLength, nullptr, nullptr);
if (outLength == 0) {
throw windows_error("string conversion failed");
}
// fix output string length (i.e. in case of unconvertible characters
while (result[outLength - 1] == L'\0') {
result.resize(--outLength);
}
}
return result;
}
};
template <>
class string_cast_impl<std::wstring, const char*>
{
public:
static std::wstring cast(const char* const& source, CodePage codePage,
size_t sourceLength)
{
std::wstring result;
if (sourceLength == std::numeric_limits<size_t>::max()) {
sourceLength = strlen(source);
}
if (sourceLength > 0) {
// use utf8 or local 8-bit encoding depending on user choice
UINT cp = windowsCP(codePage);
// preflight to find out the required source size
int outLength = MultiByteToWideChar(cp, 0, source, static_cast<int>(sourceLength),
&result[0], 0);
if (outLength == 0) {
throw windows_error("string conversion failed");
}
result.resize(outLength);
outLength = MultiByteToWideChar(cp, 0, source, static_cast<int>(sourceLength),
&result[0], outLength);
if (outLength == 0) {
throw windows_error("string conversion failed");
}
while (result[outLength - 1] == L'\0') {
result.resize(--outLength);
}
}
return result;
}
};
template <>
class string_cast_impl<std::wstring, const wchar_t*>
{
public:
static std::wstring cast(const wchar_t* const& source, CodePage, size_t)
{
return std::wstring(source);
}
};
} // namespace usvfs::shared
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