typedef vector template

Question

I'm trying to add some typedef to my class, but the compiler reports a syntax erron on the following code:

    template<class T>
    class MyClass{
        typedef std::vector<T> storageType; //this is fine
        typedef storageType::iterator iterator; //the error is here

but the next does not work too:

        typedef std::vector<T>::iterator iterator;

I was looking for the answers on many forum but i can't find a solution or workaround for this. Thank you for your help!

score 6 · Accepted Answer · edited May 23 '17 at 12:19

6

You are missing a typename:

typedef typename std::vector<T>::iterator iterator;

There are a lot of similar question. E.g. take a look at the following:

C++ template typename iterator

edited May 23 '17 at 12:19

Community

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answered Oct 19 '12 at 16:04

nosid

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score 2 · Answer 2 · answered Oct 19 '12 at 16:05

2

std::vector<T>::iterator is a dependent type so you need to add typename before it.

typedef typename std::vector<T>::iterator iterator;
        ^

answered Oct 19 '12 at 16:05

Dirk Holsopple

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Why doesn't he need it for the first one? – David G Oct 19 '12 at 16:07
`std::vector` isn't a dependent type. It's type can be determined without instantiating any templates. To determine the type of `std::vector::iterator` you have to instantiate `std::vector`. – Dirk Holsopple Oct 19 '12 at 16:09

typedef vector template

2 Answers2