shortening of datatypes

[Darkmaster]

i know it's possible, but i don't remember how.
for example you have a struct that contains another struct and that struct has a vector inside and so on, so you would need to write a lot of stuff each time you use a variable of the vector. but to shorten this you can define your own datatype/variable/namespace/..(i dont remember) and just use that instead.

hope you guys understand what i mean and can help me.

[MikeyBoy]

You can use typedef to define new types, which are basically new names for existing types.

So, for example, if you were using vectors of strings:

// Declare some vectors
std::vector<std::string> myStrings1;
std::vector<std::string> myStrings2;
std::vector<std::string> myStrings3;

// Declare a function that uses them
int Compare(const std::vector<std::string>& vector1, const std::vector<std::string>& vector2);

you could do:

// Define a new type with a helpful, descriptive name
typedef std::vector<std::string> StringVec;

// Declare some vectors
StringVec myStrings1;
StringVec myStrings2;
StringVec myStrings3;

// Declare a function that uses them
int Compare(const StringVec& vector1, const StringVec& vector2);

[Peter87]

In C++11 it's also possible to use using to do the same thing.
using StringVec = std::vector<std::string>;

[Darkmaster]

typedef is what i was searching, thanks guys

[MikeyBoy]

In C++11 it's also possible to use using to do the same thing.

Interesting. Not sure what the point of it is, though. Are there any differences between that and typedef?

Of course, I could stop being lazy and look it up myself :)

[Peter87]

I don't think there is any difference in this case, but with using you can make use of template arguments which is not possible with typedef.

template <typename T>
using HomoPair = std::pair<T, T>;

HomoPair<int> intPair;
HomoPair<std::string> stringPair;

[MikeyBoy]

Ah, OK. That's handy!