我有两个类A和B,它们都有一个像下面这样的成员:
class A {
...
std::vector<std::vector<std::vector<size_t>>> grid;
}
class B {
...
std::vector<std::vector<std::vector<size_t>>> grid;
}
我发现当我使用std::copy()
从A::grid
复制到B::grid
时,它会失败。
这是我所做的:
// Here is in B's constructor.
// I initialize B::grid with the same size of A::grid
grid = vector<vector<vector<size_t>>>(GetSetting().grid_cols());
for (int i = 0; i < GetSetting().grid_cols(); i++) {
grid[i] = vector<vector<size_t>>(GetSetting().grid_rows());
for (int j = 0; j < GetSetting().grid_rows(); j++) {
grid[i][j].reserve(a.grid[i][j].size());
}
}
// Copy from A to B
std::copy(a.grid.begin(), a.grid.end(), std::back_inserter(grid));
但是如果我删除初始化部分,那么std::copy函数就能正常工作。初始化部分有什么问题吗?
grid = a.grid;
呢? - T.C.