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Hi there,

what is the difference between const vector<const MyType> and const
vector<MyType>?

Thanks,

Barry

wrote:

> Hi there,
>
> what is the difference between const vector<const MyType> and const
> vector<MyType>?

A vector< MyType const > (const or not) invokes undefined behavior since
MyType const does not satisfy the Assignable requirement for containers. On
the other hand, vector<MyType> has this problem only if MyType does not
satisfy the requirements. If you have a good STL implementation, something
like vector< MyType const > might not even compile since concept checks
would fail.

As for const vector<X>, well, it's const: you can only call const methods on
it, which implies that you cannot change the contents of the vector after
construction (which leaves the constructor taking a range of two iterators
as the only interesting way of creating such a critter).


Best

Kai-Uwe Bux

<> wrote in message
news:b1eb5062-2bae-4df3-9b4a-...

> what is the difference between const vector<const MyType> and const
> vector<MyType>?

For one thing, const vector<const MyType> is not legal because the element
type is not assignable.