fixed_sequence.hpp

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// nros-cpp: FixedSequence — fixed-capacity sequence container
// Freestanding C++14 — no exceptions, no STL required
//
// Memory layout is repr(C) compatible: identical to { uint32_t size; T data[N]; }.
// Used by codegen-generated message structs for sequence fields.

 
#ifndef NROS_RCLCPP_FIXED_SEQUENCE_HPP
#define NROS_RCLCPP_FIXED_SEQUENCE_HPP
 
#include <cstddef>
#include <cstdint>
 
namespace rclcpp {

template <typename T, size_t N> struct FixedSequence {
    uint32_t size;
    T data[N];

    FixedSequence() : size(0), data{} {}

    bool push_back(const T& val) {
        if (size >= N) return false;
        data[size++] = val;
        return true;
    }

    T& operator[](size_t i) { return data[i]; }
    const T& operator[](size_t i) const { return data[i]; }

    uint32_t length() const { return size; }

    bool resize(size_t n) {
        if (n > N) return false;
        for (size_t i = size; i < n; ++i)
            data[i] = T();
        size = static_cast<uint32_t>(n);
        return true;
    }

    static constexpr size_t max_size() { return N; }

    T* begin() { return data; }
    T* end() { return data + size; }
    const T* begin() const { return data; }
    const T* end() const { return data + size; }
};
 
} // namespace rclcpp
 
#endif // NROS_RCLCPP_FIXED_SEQUENCE_HPP