utf8.h

#ifndef UTF8_H_
#define UTF8_H_

#include <string>

namespace utf8 {

inline size_t codePointLen(const char *src)
{
    return "\1\1\1\1\1\1\1\1\1\1\1\1\2\2\3\4"[static_cast<unsigned char>(*src)
        >> 4];
}

inline bool isTrailByte(char x) { return static_cast<signed char>(x) < -0x40; }

void replaceTabsWithSpaces(std::string *line, std::size_t tab_width = 4);

// Remove the leading UTF-8 byte order mark.
// See https://en.wikipedia.org/wiki/Byte_order_mark
inline void removeBom(std::string *s)
{
    if (s->size() >= 3 && (*s)[0] == '\xEF' && (*s)[1] == '\xBB'
        && (*s)[2] == '\xBF')
        s->erase(s->begin(), s->begin() + 3);
}

} // namespace utf8

#endif // UTF8_H_