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      1 // Copyright 2007-2010 Baptiste Lepilleur
      2 // Distributed under MIT license, or public domain if desired and
      3 // recognized in your jurisdiction.
      4 // See file LICENSE for detail or copy at http://jsoncpp.sourceforge.net/LICENSE
      5 
      6 #ifndef LIB_JSONCPP_JSON_TOOL_H_INCLUDED
      7 # define LIB_JSONCPP_JSON_TOOL_H_INCLUDED
      8 
      9 /* This header provides common string manipulation support, such as UTF-8,
     10  * portable conversion from/to string...
     11  *
     12  * It is an internal header that must not be exposed.
     13  */
     14 
     15 namespace Json {
     16 
     17 /// Converts a unicode code-point to UTF-8.
     18 static inline std::string
     19 codePointToUTF8(unsigned int cp)
     20 {
     21    std::string result;
     22 
     23    // based on description from http://en.wikipedia.org/wiki/UTF-8
     24 
     25    if (cp <= 0x7f)
     26    {
     27       result.resize(1);
     28       result[0] = static_cast<char>(cp);
     29    }
     30    else if (cp <= 0x7FF)
     31    {
     32       result.resize(2);
     33       result[1] = static_cast<char>(0x80 | (0x3f & cp));
     34       result[0] = static_cast<char>(0xC0 | (0x1f & (cp >> 6)));
     35    }
     36    else if (cp <= 0xFFFF)
     37    {
     38       result.resize(3);
     39       result[2] = static_cast<char>(0x80 | (0x3f & cp));
     40       result[1] = 0x80 | static_cast<char>((0x3f & (cp >> 6)));
     41       result[0] = 0xE0 | static_cast<char>((0xf & (cp >> 12)));
     42    }
     43    else if (cp <= 0x10FFFF)
     44    {
     45       result.resize(4);
     46       result[3] = static_cast<char>(0x80 | (0x3f & cp));
     47       result[2] = static_cast<char>(0x80 | (0x3f & (cp >> 6)));
     48       result[1] = static_cast<char>(0x80 | (0x3f & (cp >> 12)));
     49       result[0] = static_cast<char>(0xF0 | (0x7 & (cp >> 18)));
     50    }
     51 
     52    return result;
     53 }
     54 
     55 
     56 /// Returns true if ch is a control character (in range [0,32[).
     57 static inline bool
     58 isControlCharacter(char ch)
     59 {
     60    return ch > 0 && ch <= 0x1F;
     61 }
     62 
     63 
     64 enum {
     65    /// Constant that specify the size of the buffer that must be passed to uintToString.
     66    uintToStringBufferSize = 3*sizeof(LargestUInt)+1
     67 };
     68 
     69 // Defines a char buffer for use with uintToString().
     70 typedef char UIntToStringBuffer[uintToStringBufferSize];
     71 
     72 
     73 /** Converts an unsigned integer to string.
     74  * @param value Unsigned interger to convert to string
     75  * @param current Input/Output string buffer.
     76  *        Must have at least uintToStringBufferSize chars free.
     77  */
     78 static inline void
     79 uintToString( LargestUInt value,
     80               char *&current )
     81 {
     82    *--current = 0;
     83    do
     84    {
     85       *--current = char(value % 10) + '0';
     86       value /= 10;
     87    }
     88    while ( value != 0 );
     89 }
     90 
     91 } // namespace Json {
     92 
     93 #endif // LIB_JSONCPP_JSON_TOOL_H_INCLUDED
     94