vector.h

Go to the documentation of this file.

#pragma once
 
#include <absl/container/inlined_vector.h>
 
#include "mim/util/span.h"
 
namespace mim {
 
template<class T> static constexpr size_t Default_Inlined_Size = std::max((size_t)1, 4 * sizeof(size_t) / sizeof(T));
 
/// This is a thin wrapper for [`absl::InlinedVector<T, N,
/// A>`](https://github.com/abseil/abseil-cpp/blob/master/absl/container/inlined_vector.h) which in turn is a drop-in
/// replacement for [`std::vector<T, A>`](https://en.cppreference.com/w/cpp/container/vector). In addition, there are
/// generator-like/lambda-based constructors and conversions to Span available.
template<class T, size_t N = Default_Inlined_Size<T>, class A = std::allocator<T>>
class Vector : public absl::InlinedVector<T, N, A> {
public:
    using Base = absl::InlinedVector<T, N, A>;
 
    /// @name Constructors
    ///@{
    using Base::Base;
    template<class F>
    constexpr explicit Vector(size_t size, F&& f) requires(std::is_invocable_r_v<T, F, size_t>)
        : Base(size) {
        for (size_t i = 0; i != size; ++i) (*this)[i] = std::invoke(f, i);
    }
    template<std::ranges::forward_range R, class F>
    constexpr explicit Vector(const R& range, F&& f)
        requires(std::is_invocable_r_v<T, F, decltype(*std::ranges::begin(range))>)
        : Base(std::ranges::distance(range)) {
        auto ri = std::ranges::begin(range);
        for (auto& elem : *this) elem = std::invoke(f, *ri++);
    }
    ///@}
 
    /// @name Span
    ///@{
    Span<T> span() { return Span(Base::data(), Base::size()); }
    Span<const T> span() const { return Span(Base::data(), Base::size()); }
    Span<const T> view() const { return Span(Base::data(), Base::size()); }
    ///@}
 
    friend void swap(Vector& v1, Vector& v2) noexcept(noexcept(v1.swap(v2))) { v1.swap(v2); }
};
 
static_assert(std::ranges::contiguous_range<Vector<int>>);
 
/// @name Deduction Guides
///@{
template<class I, class A = std::allocator<typename std::iterator_traits<I>::value_type>>
Vector(I, I, A = A()) -> Vector<typename std::iterator_traits<I>::value_type,
                                Default_Inlined_Size<typename std::iterator_traits<I>::value_type>,
                                A>;
///@}
 
/// @name erase
// TODO needed
///@{
template<class T, size_t N, class A, class U>
constexpr typename Vector<T, N, A>::size_type erase(Vector<T, N, A>& c, const U& value) {
    auto it = std::remove(c.begin(), c.end(), value);
    auto r  = c.end() - it;
    c.erase(it, c.end());
    return r;
}
 
template<class T, size_t N, class A, class Pred>
constexpr typename Vector<T, N, A>::size_type erase_if(Vector<T, N, A>& c, Pred pred) {
    auto it = std::remove_if(c.begin(), c.end(), pred);
    auto r  = c.end() - it;
    c.erase(it, c.end());
    return r;
}
///@}
 
} // namespace mim