CODEWITHSUNDEEP
c++
GregH
GregH

Reputation: 12858

Can somebody interpret this C++ line of code?

Sorry, I'm a C++ novice. I was looking through some code and ran across this line of code:

   string cmd(*iter);

Obviously the variable "cmd" is being defined as a string, but the part that I don't understand is the bit inside the parenthesis: (*iter)

I know the "*iter" is a pointer but what does it mean to have a variable declaration followed by parenthesis?

Sorry for such a dumb question.

Upvotes: 0

Views: 98

Answers (4)

AnT stands with Russia
AnT stands with Russia

Reputation: 320361

In "classic" C++ language you have two forms of initialization syntax:

copy-initialization

int i = 5;

and direct-initialization

int i(5);

They are not always exactly the same, but for basic intents and purposes they do the same thing. (C++11 further extended the variety, but I won't go into that here.) In my above examples they are actually exactly the same: variable i will be initialized with 5 in both cases.

So your

string cmd(*iter);

has the same effect as 

string cmd = *iter;

i.e. it initializes string cmd with value of *iter, where iter is probably an iterator of some kind.

Assuming string is actually the std::string class from Standard Library, your string cmd(*iter) will invoke one of std::strings constructors. Which one - depends on the type of *iter.

Upvotes: 3

Heartwork
Heartwork

Reputation: 41

initialize string cmd via *iter.

NOTE: iter does not necessarily have to be a pointer, it could also be an iterator.

You should check the iterator's * operator.

Upvotes: 3

xxbbcc
xxbbcc

Reputation: 17327

It calls the constructor of string with the value pointed by iter. This line of code simply creates a new string instance called cmd and initializes to the value of the iterator.

Upvotes: 1

ivarec
ivarec

Reputation: 2612

It is calling the constructor of the string class which accepts this kind of parameter. The same class can have different constructors.

Upvotes: 1

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