libcruft-util/types.cpp

171 lines
4.5 KiB
C++

/*
* This file is part of libgim.
*
* libgim 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.
*
* libgim 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 libgim. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2011 Danny Robson <danny@nerdcruft.net>
*/
#include "types.hpp"
#include <type_traits>
using namespace std;
#define do_type_to_string(T) \
template <> std::string type_to_string <T> (void) { return #T; } \
template <> std::string type_to_string <const T> (void) { return "const " #T; }
do_type_to_string (float)
do_type_to_string (double)
do_type_to_string ( int8_t)
do_type_to_string ( int16_t)
do_type_to_string ( int32_t)
do_type_to_string ( int64_t)
do_type_to_string ( uint8_t)
do_type_to_string (uint16_t)
do_type_to_string (uint32_t)
do_type_to_string (uint64_t)
#ifdef WORDS_BIGENDIAN
/* Big endian doesn't need swapping */
template <typename T>
T hton (T val) {
static_assert (is_fundamental <T>(), "hton implementation assumes fundamental types");
static_assert (is_unsigned <T>(), "hton implementation does not handle signed");
return val;
}
template <typename T>
T ntoh (T val) {
static_assert (is_fundamental <T>(), "ntoh implementation assumes fundamental types");
static_assert (is_unsigned <T>(), "ntoh implementation does not handle signed");
return val;
}
template <> uint8_t hton ( uint8_t);
template <> uint16_t hton (uint16_t);
template <> uint32_t hton (uint32_t);
template <> uint64_t hton (uint64_t);
template <> uint8_t ntoh ( uint8_t);
template <> uint16_t ntoh (uint16_t);
template <> uint32_t ntoh (uint32_t);
template <> uint64_t ntoh (uint64_t);
#else
static void
byte_swap (uint8_t *restrict dst, uint8_t *restrict src, size_t len) {
for (unsigned int i = 0; i < len; ++i)
dst[len - i - 1] = src[i];
}
template <typename T>
T
hton (T i) {
// Unsure if this will really be sensible for non-intrinsic types, or types larger than 8 bytes.
static_assert (is_fundamental <T>::value, "hton implementation assumes fundamental types");
static_assert (is_unsigned <T>::value, "hton implementation does not handle signed");
T swapped;
byte_swap (reinterpret_cast <uint8_t*>(&swapped),
reinterpret_cast <uint8_t*>(&i),
sizeof (T));
return swapped;
}
template <typename T>
T
ntoh (T i) {
// Unsure if this will really be sensible for non-intrinsic types, or types larger than 8 bytes.
static_assert (is_fundamental <T>::value, "ntoh implementation assumes fundamental types");
static_assert (is_unsigned <T>::value, "ntoh implementation does not handle signed");
T swapped;
byte_swap (reinterpret_cast <uint8_t*>(&swapped),
reinterpret_cast <uint8_t*>(&i),
sizeof (T));
return swapped;
}
template <> uint8_t hton (uint8_t i) { return i; }
template <> uint8_t ntoh (uint8_t i) { return i; }
template uint16_t ntoh<uint16_t> (uint16_t);
template uint32_t ntoh<uint32_t> (uint32_t);
template uint64_t ntoh<uint64_t> (uint64_t);
template uint16_t hton<uint16_t> (uint16_t);
template uint32_t hton<uint32_t> (uint32_t);
template uint64_t hton<uint64_t> (uint64_t);
#endif
fourcc
fourcc::from_chars (uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
fourcc lhs;
lhs.data[0] = a;
lhs.data[1] = b;
lhs.data[2] = c;
lhs.data[3] = d;
return lhs;
}
fourcc
fourcc::from_str (const char data[4]) {
fourcc lhs;
lhs.data[0] = (uint8_t)data[0];
lhs.data[1] = (uint8_t)data[1];
lhs.data[2] = (uint8_t)data[2];
lhs.data[3] = (uint8_t)data[3];
return lhs;
}
bool
fourcc::operator== (const char rhs[4]) const {
return data[0] == rhs[0] &&
data[1] == rhs[1] &&
data[2] == rhs[2] &&
data[3] == rhs[3];
}
fourcc::operator uint32_t (void) const {
return (uint32_t)(data[0] << 24U |
data[1] << 16U |
data[2] << 8U |
data[3]);
}
ostream&
operator<< (ostream &os, fourcc f) {
os << f.data[0] << f.data[1] << f.data[2] << f.data[3];
return os;
}