1 files changed, 170 insertions, 0 deletions
diff --git a/libs/usvfs/src/shared/stringcast.h b/libs/usvfs/src/shared/stringcast.h
new file mode 100644
index 0000000..0ce56d1
--- /dev/null
+++ b/libs/usvfs/src/shared/stringcast.h
@@ -0,0 +1,170 @@
+/*
+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