98 lines
3.9 KiB
C++
98 lines
3.9 KiB
C++
#ifndef _C4_STD_STRING_HPP_
|
|
#define _C4_STD_STRING_HPP_
|
|
|
|
/** @file string.hpp */
|
|
|
|
#ifndef C4CORE_SINGLE_HEADER
|
|
#include "c4/substr.hpp"
|
|
#endif
|
|
|
|
#include <string>
|
|
|
|
namespace c4 {
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
/** get a writeable view to an existing std::string.
|
|
* When the string is empty, the returned view will be pointing
|
|
* at the character with value '\0', but the size will be zero.
|
|
* @see https://en.cppreference.com/w/cpp/string/basic_string/operator_at
|
|
*/
|
|
C4_ALWAYS_INLINE c4::substr to_substr(std::string &s) noexcept
|
|
{
|
|
#if C4_CPP < 11
|
|
#error this function will have undefined behavior
|
|
#endif
|
|
// since c++11 it is legal to call s[s.size()].
|
|
return c4::substr(&s[0], s.size());
|
|
}
|
|
|
|
/** get a readonly view to an existing std::string.
|
|
* When the string is empty, the returned view will be pointing
|
|
* at the character with value '\0', but the size will be zero.
|
|
* @see https://en.cppreference.com/w/cpp/string/basic_string/operator_at
|
|
*/
|
|
C4_ALWAYS_INLINE c4::csubstr to_csubstr(std::string const& s) noexcept
|
|
{
|
|
#if C4_CPP < 11
|
|
#error this function will have undefined behavior
|
|
#endif
|
|
// since c++11 it is legal to call s[s.size()].
|
|
return c4::csubstr(&s[0], s.size());
|
|
}
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
C4_ALWAYS_INLINE bool operator== (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) == 0; }
|
|
C4_ALWAYS_INLINE bool operator!= (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) != 0; }
|
|
C4_ALWAYS_INLINE bool operator>= (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) >= 0; }
|
|
C4_ALWAYS_INLINE bool operator> (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) > 0; }
|
|
C4_ALWAYS_INLINE bool operator<= (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) <= 0; }
|
|
C4_ALWAYS_INLINE bool operator< (c4::csubstr ss, std::string const& s) { return ss.compare(to_csubstr(s)) < 0; }
|
|
|
|
C4_ALWAYS_INLINE bool operator== (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) == 0; }
|
|
C4_ALWAYS_INLINE bool operator!= (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) != 0; }
|
|
C4_ALWAYS_INLINE bool operator>= (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) <= 0; }
|
|
C4_ALWAYS_INLINE bool operator> (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) < 0; }
|
|
C4_ALWAYS_INLINE bool operator<= (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) >= 0; }
|
|
C4_ALWAYS_INLINE bool operator< (std::string const& s, c4::csubstr ss) { return ss.compare(to_csubstr(s)) > 0; }
|
|
|
|
//-----------------------------------------------------------------------------
|
|
|
|
/** copy an std::string to a writeable string view */
|
|
inline size_t to_chars(c4::substr buf, std::string const& s)
|
|
{
|
|
C4_ASSERT(!buf.overlaps(to_csubstr(s)));
|
|
size_t len = buf.len < s.size() ? buf.len : s.size();
|
|
// calling memcpy with null strings is undefined behavior
|
|
// and will wreak havoc in calling code's branches.
|
|
// see https://github.com/biojppm/rapidyaml/pull/264#issuecomment-1262133637
|
|
if(len)
|
|
{
|
|
C4_ASSERT(s.data() != nullptr);
|
|
C4_ASSERT(buf.str != nullptr);
|
|
memcpy(buf.str, s.data(), len);
|
|
}
|
|
return s.size(); // return the number of needed chars
|
|
}
|
|
|
|
/** copy a string view to an existing std::string */
|
|
inline bool from_chars(c4::csubstr buf, std::string * s)
|
|
{
|
|
s->resize(buf.len);
|
|
C4_ASSERT(!buf.overlaps(to_csubstr(*s)));
|
|
// calling memcpy with null strings is undefined behavior
|
|
// and will wreak havoc in calling code's branches.
|
|
// see https://github.com/biojppm/rapidyaml/pull/264#issuecomment-1262133637
|
|
if(buf.len)
|
|
{
|
|
C4_ASSERT(buf.str != nullptr);
|
|
memcpy(&(*s)[0], buf.str, buf.len);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
} // namespace c4
|
|
|
|
#endif // _C4_STD_STRING_HPP_
|