Function test_map_iterators

tests/test_container_helpers.h:778–810

// Verifies: begin/end, forward iteration, const iteration
template<template<typename, typename> class MapTemplate>
void test_map_iterators() {
    using MapContainer = MapTemplate<int, fl::shared_ptr<int>>;

    auto ptr1 = make_shared_int(10);
    auto ptr2 = make_shared_int(20);
    auto ptr3 = make_shared_int(30);

    MapContainer source;
    populate_map(source, 1, ptr1);
    populate_map(source, 2, ptr2);
    populate_map(source, 3, ptr3);

    // Test mutable iterators exist
    FL_CHECK(source.begin() != source.end());

    // Test const iterators via const reference
    const auto& const_source = source;
    FL_CHECK(const_source.begin() != const_source.end());

    // Test iteration - count elements
    int count = 0;
    for (auto it = source.begin(); it != source.end(); ++it) {
        count++;
    }
    FL_CHECK(count == 3);

    // Move and verify source is empty via iterators
    MapContainer destination = fl::move(source);
    FL_CHECK(source.begin() == source.end());  // Empty after move
    const auto& const_empty = source;
    FL_CHECK(const_empty.begin() == const_empty.end());
    FL_CHECK(destination.begin() != destination.end());  // Has elements
}

// Test reverse iterator support for map containers
// Verifies: rbegin/rend work correctly