update upf8 from 2.3.4 to 3.2.3

New convenience API for C++ 11 and later compilers. The library still works with C++ 98/03 compliant compilers, just without the new functions.
advance() function works in both directions.
The following deprecated functions were removed:

previous() - deprecated since version 1.02.
is_bom() - deprecated since version 2.3.
Fix of the project version number at CMakeLists.txt
Continuous Integration with Google Tests and CircleCI
A minor release that contains fix for Issue #31 Program fails to link when including utf8.h in multiple files.
This release adds one new API call: unchecked::replace_invalid().
Optional support for C++ 17 std::string_view.
The release contains the fix the inclusion of both cpp11 and cpp17 headers on C++17 compilation. Also some additional tests for using string literals and string objects with modern compilers.

contrib/utf8cpp/doc/LICENSE

@@ -0,0 +1,23 @@
+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.

contrib/utf8cpp/doc/ReleaseNotes

@@ -1,12 +0,0 @@
-utf8 cpp library
-Release 2.3.4
-
-A minor bug fix release. Thanks to all who reported bugs. 
-
-Note: Version 2.3.3 contained a regression, and therefore was removed.
-
-Changes from version 2.3.2
-- Bug fix [39]: checked.h Line 273 and unchecked.h Line 182 have an extra ';'
-- Bug fix [36]: replace_invalid() only works with back_inserter
-
-Files included in the release: utf8.h, core.h, checked.h, unchecked.h, utf8cpp.html, ReleaseNotes

contrib/utf8cpp/source/utf8/checked.h

@@ -42,7 +42,7 @@ namespace utf8
         uint32_t cp;
     public:
         invalid_code_point(uint32_t codepoint) : cp(codepoint) {}
-        virtual const char* what() const NOEXCEPT OVERRIDE { return "Invalid code point"; }
+        virtual const char* what() const UTF_CPP_NOEXCEPT UTF_CPP_OVERRIDE { return "Invalid code point"; }
         uint32_t code_point() const {return cp;}
     };
 
@@ -50,7 +50,8 @@ namespace utf8
         uint8_t u8;
     public:
         invalid_utf8 (uint8_t u) : u8(u) {}
-        virtual const char* what() const NOEXCEPT OVERRIDE { return "Invalid UTF-8"; }
+        invalid_utf8 (char c) : u8(static_cast<uint8_t>(c)) {}
+        virtual const char* what() const UTF_CPP_NOEXCEPT UTF_CPP_OVERRIDE { return "Invalid UTF-8"; }
         uint8_t utf8_octet() const {return u8;}
     };
 
@@ -58,13 +59,13 @@ namespace utf8
         uint16_t u16;
     public:
         invalid_utf16 (uint16_t u) : u16(u) {}
-        virtual const char* what() const NOEXCEPT OVERRIDE { return "Invalid UTF-16"; }
+        virtual const char* what() const UTF_CPP_NOEXCEPT UTF_CPP_OVERRIDE { return "Invalid UTF-16"; }
         uint16_t utf16_word() const {return u16;}
     };
 
     class not_enough_room : public exception {
     public:
-        virtual const char* what() const NOEXCEPT OVERRIDE { return "Not enough space"; }
+        virtual const char* what() const UTF_CPP_NOEXCEPT UTF_CPP_OVERRIDE { return "Not enough space"; }
     };
 
     /// The library API - functions intended to be called by the users
@@ -75,24 +76,7 @@ namespace utf8
         if (!utf8::internal::is_code_point_valid(cp))
             throw invalid_code_point(cp);
 
-        if (cp < 0x80)                        // one octet
+        return internal::append(cp, result);
-            *(result++) = static_cast<uint8_t>(cp);
-        else if (cp < 0x800) {                // two octets
-            *(result++) = static_cast<uint8_t>((cp >> 6)            | 0xc0);
-            *(result++) = static_cast<uint8_t>((cp & 0x3f)          | 0x80);
-        }
-        else if (cp < 0x10000) {              // three octets
-            *(result++) = static_cast<uint8_t>((cp >> 12)           | 0xe0);
-            *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f)   | 0x80);
-            *(result++) = static_cast<uint8_t>((cp & 0x3f)          | 0x80);
-        }
-        else {                                // four octets
-            *(result++) = static_cast<uint8_t>((cp >> 18)           | 0xf0);
-            *(result++) = static_cast<uint8_t>(((cp >> 12) & 0x3f)  | 0x80);
-            *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f)   | 0x80);
-            *(result++) = static_cast<uint8_t>((cp & 0x3f)          | 0x80);
-        }
-        return result;
     }
 
     template <typename octet_iterator, typename output_iterator>
@@ -148,7 +132,7 @@ namespace utf8
             case internal::INVALID_LEAD :
             case internal::INCOMPLETE_SEQUENCE :
             case internal::OVERLONG_SEQUENCE :
-                throw invalid_utf8(*it);
+                throw invalid_utf8(static_cast<uint8_t>(*it));
             case internal::INVALID_CODE_POINT :
                 throw invalid_code_point(cp);
         }
@@ -325,7 +309,9 @@ namespace utf8
 
 } // namespace utf8
 
-#if UTF_CPP_CPLUSPLUS >= 201103L // C++ 11 or later
+#if UTF_CPP_CPLUSPLUS >= 201703L // C++ 17 or later
+#include "cpp17.h"
+#elif UTF_CPP_CPLUSPLUS >= 201103L // C++ 11 or later
 #include "cpp11.h"
 #endif // C++ 11 or later
 

contrib/utf8cpp/source/utf8/core.h

@@ -39,11 +39,11 @@ DEALINGS IN THE SOFTWARE.
 #endif
 
 #if UTF_CPP_CPLUSPLUS >= 201103L // C++ 11 or later
-    #define OVERRIDE override
+    #define UTF_CPP_OVERRIDE override
-    #define NOEXCEPT noexcept
+    #define UTF_CPP_NOEXCEPT noexcept
 #else // C++ 98/03
-    #define OVERRIDE
+    #define UTF_CPP_OVERRIDE
-    #define NOEXCEPT throw()
+    #define UTF_CPP_NOEXCEPT throw()
 #endif // C++ 11 or later
 
 
@@ -297,6 +297,55 @@ namespace internal
         return utf8::internal::validate_next(it, end, ignored);
     }
 
+    // Internal implementation of both checked and unchecked append() function
+    // This function will be invoked by the overloads below, as they will know
+    // the octet_type.
+    template <typename octet_iterator, typename octet_type>
+    octet_iterator append(uint32_t cp, octet_iterator result) {
+        if (cp < 0x80)                        // one octet
+            *(result++) = static_cast<octet_type>(cp);
+        else if (cp < 0x800) {                // two octets
+            *(result++) = static_cast<octet_type>((cp >> 6)          | 0xc0);
+            *(result++) = static_cast<octet_type>((cp & 0x3f)        | 0x80);
+        }
+        else if (cp < 0x10000) {              // three octets
+            *(result++) = static_cast<octet_type>((cp >> 12)         | 0xe0);
+            *(result++) = static_cast<octet_type>(((cp >> 6) & 0x3f) | 0x80);
+            *(result++) = static_cast<octet_type>((cp & 0x3f)        | 0x80);
+        }
+        else {                                // four octets
+            *(result++) = static_cast<octet_type>((cp >> 18)         | 0xf0);
+            *(result++) = static_cast<octet_type>(((cp >> 12) & 0x3f)| 0x80);
+            *(result++) = static_cast<octet_type>(((cp >> 6) & 0x3f) | 0x80);
+            *(result++) = static_cast<octet_type>((cp & 0x3f)        | 0x80);
+        }
+        return result;
+    }
+    
+    // One of the following overloads will be invoked from the API calls
+
+    // A simple (but dangerous) case: the caller appends byte(s) to a char array
+    inline char* append(uint32_t cp, char* result) {
+        return append<char*, char>(cp, result);
+    }
+
+    // Hopefully, most common case: the caller uses back_inserter
+    // i.e. append(cp, std::back_inserter(str));
+    template<typename container_type>
+    std::back_insert_iterator<container_type> append
+            (uint32_t cp, std::back_insert_iterator<container_type> result) {
+        return append<std::back_insert_iterator<container_type>,
+            typename container_type::value_type>(cp, result);
+    }
+
+    // The caller uses some other kind of output operator - not covered above
+    // Note that in this case we are not able to determine octet_type
+    // so we assume it's uint_8; that can cause a conversion warning if we are wrong.
+    template <typename octet_iterator>
+    octet_iterator append(uint32_t cp, octet_iterator result) {
+        return append<octet_iterator, uint8_t>(cp, result);
+    }
+
 } // namespace internal
 
     /// The library API - functions intended to be called by the users

contrib/utf8cpp/source/utf8/cpp11.h

@@ -70,7 +70,7 @@ namespace utf8
     inline std::size_t find_invalid(const std::string& s)
     {
         std::string::const_iterator invalid = find_invalid(s.begin(), s.end());
-        return (invalid == s.end()) ? std::string::npos : (invalid - s.begin());
+        return (invalid == s.end()) ? std::string::npos : static_cast<std::size_t>(invalid - s.begin());
     }
 
     inline bool is_valid(const std::string& s)

contrib/utf8cpp/source/utf8/cpp17.h

@@ -0,0 +1,103 @@
+// Copyright 2018 Nemanja Trifunovic
+
+/*
+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 UTF8_FOR_CPP_7e906c01_03a3_4daf_b420_ea7ea952b3c9
+#define UTF8_FOR_CPP_7e906c01_03a3_4daf_b420_ea7ea952b3c9
+
+#include "checked.h"
+#include <string>
+
+namespace utf8
+{
+
+    inline void append(char32_t cp, std::string& s)
+    {
+        append(uint32_t(cp), std::back_inserter(s));
+    }
+
+    inline std::string utf16to8(std::u16string_view s)
+    {
+        std::string result;
+        utf16to8(s.begin(), s.end(), std::back_inserter(result));
+        return result;
+    }
+
+    inline std::u16string utf8to16(std::string_view s)
+    {
+        std::u16string result;
+        utf8to16(s.begin(), s.end(), std::back_inserter(result));
+        return result;
+    }
+
+    inline std::string utf32to8(std::u32string_view s)
+    {
+        std::string result;
+        utf32to8(s.begin(), s.end(), std::back_inserter(result));
+        return result;
+    }
+
+    inline std::u32string utf8to32(std::string_view s)
+    {
+        std::u32string result;
+        utf8to32(s.begin(), s.end(), std::back_inserter(result));
+        return result;
+    }
+
+    inline std::size_t find_invalid(std::string_view s)
+    {
+        std::string_view::const_iterator invalid = find_invalid(s.begin(), s.end());
+        return (invalid == s.end()) ? std::string_view::npos : static_cast<std::size_t>(invalid - s.begin());
+    }
+
+    inline bool is_valid(std::string_view s)
+    {
+        return is_valid(s.begin(), s.end());
+    }
+
+    inline std::string replace_invalid(std::string_view s, char32_t replacement)
+    {
+        std::string result;
+        replace_invalid(s.begin(), s.end(), std::back_inserter(result), replacement);
+        return result;
+    }
+
+    inline std::string replace_invalid(std::string_view s)
+    {
+        std::string result;
+        replace_invalid(s.begin(), s.end(), std::back_inserter(result));
+        return result;
+    }
+
+    inline bool starts_with_bom(std::string_view s)
+    {
+        return starts_with_bom(s.begin(), s.end());
+    }
+ 
+} // namespace utf8
+
+#endif // header guard
+

contrib/utf8cpp/source/utf8/unchecked.h

@@ -37,24 +37,7 @@ namespace utf8
         template <typename octet_iterator>
         octet_iterator append(uint32_t cp, octet_iterator result)
         {
-            if (cp < 0x80)                        // one octet
+            return internal::append(cp, result);
-                *(result++) = static_cast<uint8_t>(cp);
-            else if (cp < 0x800) {                // two octets
-                *(result++) = static_cast<uint8_t>((cp >> 6)          | 0xc0);
-                *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
-            }
-            else if (cp < 0x10000) {              // three octets
-                *(result++) = static_cast<uint8_t>((cp >> 12)         | 0xe0);
-                *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
-                *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
-            }
-            else {                                // four octets
-                *(result++) = static_cast<uint8_t>((cp >> 18)         | 0xf0);
-                *(result++) = static_cast<uint8_t>(((cp >> 12) & 0x3f)| 0x80);
-                *(result++) = static_cast<uint8_t>(((cp >> 6) & 0x3f) | 0x80);
-                *(result++) = static_cast<uint8_t>((cp & 0x3f)        | 0x80);
-            }
-            return result;
         }
 
         template <typename octet_iterator, typename output_iterator>