Aliasing vector correctly

Question

I have not been able to find the answer elsewhere, so I guess I just have to ask this one: I am trying to get an alias for a vector (in which int pointers are stored), as below: ``` void conversion(Engine * ENGINES) {//The Engine class has a vector of int* as a public data member called SITE for (int i = 0; i < 3; i++) { vector * current = &(ENGINES[i].SITE);//the problematic line int j_max = current -> size(); cout << j_max << endl; for (int j = 0; j < j_max; j++) { for (int k = 0; k < 3; k++) { if (*current[j][k] == 2) *current[j][k] = 1; if (*current[j][k] == -1) *current[j][k] = 0; } } } } ``` The problem is that there seems to be an inversion of the indices for the *current[a][b]. I want to be able to use current as a normal vector, but now the indexing is reversed compared to: ``` vector current1 = ENGINES[1].SITE; ``` so that `*current[i][j] = current1[j][i]` for some reason. Is there a mistake in my syntax?

Accepted Answer

I believe your problem is that `[]` has higher precedence than unary `*`. So you're getting `*(current[j][k])` instead of `(*current)[j][k]`, which is what you want.

However you could eliminate that problem by just taking a reference rather than a pointer:

`vector <int*>& current = (ENGINES[i].SITE);` and then just remove your extra loading `*` operators on access to `current`.

Aliasing vector correctly

Solution

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