Using std::vector as view on to raw memory

Question

I\'m using a external library which at some point gives me a raw pointer to an array of integers and a size.

Now I\'d like to use std::vector to access and

Answer 1

Besides the other good suggestion about std::span coming in c++20 and gsl:span, including your own (lightweight) span class until then is easy enough already (feel free to copy):

template
struct span {
    T* first;
    size_t length;
    span(T* first_, size_t length_) : first(first_), length(length_) {};
    using value_type = std::remove_cv_t;//primarily needed if used with templates
    bool empty() const { return length == 0; }
    auto begin() const { return first; }
    auto end() const { return first + length; }
};

static_assert(_MSVC_LANG <= 201703L, "remember to switch to std::span");

Of special note is also the boost range library boost-range if you are interested in the more generic range concept: https://www.boost.org/doc/libs/1_60_0/libs/range/doc/html/range/reference/utilities/iterator_range.html.

Range concepts will also arrive in c++20