csm2.hpp

来自「C++_Templates这本书的随书源码」· HPP 代码 · 共 42 行

/* The following code example is taken from the book
 * "C++ Templates - The Complete Guide"
 * by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
 *
 * (C) Copyright David Vandevoorde and Nicolai M. Josuttis 2002.
 * Permission to copy, use, modify, sell and distribute this software
 * is granted provided this copyright notice appears in all copies.
 * This software is provided "as is" without express or implied
 * warranty, and with no claim as to its suitability for any purpose.
 */
#include <cstring>
#include <cassert>
#include <stddef.h>
#include "csm1.hpp"

// partial specialization for fast bitwise copying of objects
template <typename T>
class BitOrClassCSM<T,true> : public BitOrClassCSM<T,false> {
  public:
    static void copy_n (T const* src, T* dst, size_t n) {
        // copy n items onto n other ones
        std::memcpy((void*)dst, (void*)src, n*sizeof(T));
    }

    static void copy_init_n (T const* src, void* dst, size_t n) {
        // copy n items onto uninitialized storage
        std::memcpy(dst, (void*)src, n*sizeof(T));
    }

    static void move_n (T* src, T* dst, size_t n) {
        // move n items onto n other ones
        assert(src != dst);
        std::memcpy((void*)dst, (void*)src, n*sizeof(T));
    }

    static void move_init_n (T const* src, void* dst, size_t n) {
        // move n items onto uninitialized storage
        assert(src != dst);
        std::memcpy(dst, (void*)src, n*sizeof(T));
    }
};