我用這個代碼:C++:如何使用memcpy與指針**?
memcpy(arr[i], arr1[i], sizeof(arr1[i]));
與定義:
double** arr; // arr1 is difined the same way.
arr = new double*[row];
for (int i = 0; i < row; ++i) {
arr[i] = new double[col];
memcpy(arr[i], arr1[i], sizeof(arr1[i]));
}
我用命令建立它:g++ -Wall -Wextra -Wpedantic -c arr.cpp
並有結果:
警告:在「無效參數 '的sizeof' * memcpy(void *,const void *,size_t)'調用與目標相同的指針類型'double *';預期「雙倍」或明確的長度[-Wsizeof-pointer-memaccess]
memcpy(arr[i], arr1[i], sizeof(arr1[i]));
^
我不明白它是什麼。你能告訴我如何使它正常工作?
閱讀此:http://stackoverflow.com/q/2681061/69537 – Meysam