diff --git a/src/util/stack_vector.hpp b/src/util/stack_vector.hpp index a167d1d7..32902d86 100644 --- a/src/util/stack_vector.hpp +++ b/src/util/stack_vector.hpp @@ -5,20 +5,30 @@ namespace util { template class stack_vector { + struct buffer { + alignas(alignof(T)) char* data[sizeof(T) * capacity]; + + T* ptr() { + return reinterpret_cast(data); + } + const T* ptr() const { + return reinterpret_cast(data); + } + }; public: stack_vector() : size_(0) {} stack_vector(const stack_vector& other) : size_(other.size_) { for (int i = 0; i < size_; ++i) { - new (&data_[i]) T(other.data_[i]); + new (&data_.ptr()[i]) T(other.data_.ptr()[i]); } } stack_vector(stack_vector&& other) noexcept : size_(other.size_) { for (int i = 0; i < size_; ++i) { - new (&data_[i]) T(std::move(other.data_[i])); + new (&data_.ptr()[i]) T(std::move(other.data_.ptr()[i])); } other.size_ = 0; } @@ -29,17 +39,25 @@ namespace util { "initializer list exceeds stack vector capacity" ); for (const auto& value : init) { - new (&data_[size_++]) T(value); + new (&data_.ptr()[size_++]) T(value); } } - ~stack_vector() { - clear(); - } + ~stack_vector() = default; void push_back(const T& value) { if (size_ < capacity) { - data_[size_++] = value; + auto data = reinterpret_cast(data_.ptr() + (size_++)); + new (data) T(value); + } else { + throw std::overflow_error("stack vector capacity exceeded"); + } + } + + void push_back(T&& value) { + if (size_ < capacity) { + auto data = reinterpret_cast(data_.ptr() + (size_++)); + new (data) T(std::move(value)); } else { throw std::overflow_error("stack vector capacity exceeded"); } @@ -47,7 +65,7 @@ namespace util { void pop_back() { if (size_ > 0) { - data_[size_ - 1].~T(); + data_.ptr()[size_ - 1].~T(); --size_; } else { throw std::underflow_error("stack vector is empty"); @@ -56,31 +74,31 @@ namespace util { void clear() { for (int i = 0; i < size_; ++i) { - data_[i].~T(); + data_.ptr()[i].~T(); } size_ = 0; } T& operator[](int index) { - return data_[index]; + return data_.ptr()[index]; } const T& operator[](int index) const { - return data_[index]; + return data_.ptr()[index]; } T& at(int index) { if (index < 0 || index >= size_) { throw std::out_of_range("index out of range"); } - return data_[index]; + return data_.ptr()[index]; } const T& at(int index) const { if (index < 0 || index >= size_) { throw std::out_of_range("index out of range"); } - return data_[index]; + return data_.ptr()[index]; } int size() const { @@ -96,22 +114,22 @@ namespace util { } auto begin() { - return data_; + return data_.ptr(); } auto end() { - return data_ + size_; + return data_.ptr() + size_; } auto begin() const { - return data_; + return data_.ptr(); } auto end() const { - return data_ + size_; + return data_.ptr() + size_; } private: - T data_[capacity]; + buffer data_; int size_; }; } diff --git a/test/util/stack_vector.cpp b/test/util/stack_vector.cpp new file mode 100644 index 00000000..ec3edc89 --- /dev/null +++ b/test/util/stack_vector.cpp @@ -0,0 +1,20 @@ +#include +#include + +#include "util/stack_vector.hpp" + +using namespace util; + +TEST(util, stack_vector) { + stack_vector vec; + vec.push_back("hello"); + vec.push_back("world"); + vec.push_back("?"); + ASSERT_EQ(3, vec.size()); + vec.pop_back(); + ASSERT_EQ(2, vec.size()); + vec.clear(); + ASSERT_EQ(0, vec.size()); + ASSERT_TRUE(vec.empty()); + vec.push_back("test"); +}