std::transform using C++0x lambda expression

Question

How is this done in C++0x?

std::vector myv1;
std::transform(myv1.begin(), myv1.end(), myv1.begin(),
               std::bind1st(std::multiplies         


        

Answer 1

Using a mutable approach, we can use for_each to directly update the sequence elements through references.

for_each(begin(myv1), end(myv1), [](double& a) { a *= 3; });

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There has been some debate going on if for_each is actually allowed to modify elements as it's called a "non-mutating" algorithm.

What that means is for_each isn't allowed to alter the sequence it operates on (which refers to changes of the sequence structure - i.e. invalidating iterators). This doesn't mean we cannot modify the non-const elements of the vector as usual - the structure itself is left untouched by these operations.