godot_voxel/util/array_slice.h

79 lines
1.5 KiB
C++

#ifndef ARRAY_SLICE_H
#define ARRAY_SLICE_H
#include "fixed_array.h"
#include <core/error_macros.h>
#include <vector>
// View into an array, referencing a pointer and a size.
template <typename T>
class ArraySlice {
public:
inline ArraySlice() :
_ptr(nullptr),
_size(0) {
}
// TODO Get rid of unsafe constructor, use specialized ones
inline ArraySlice(T *p_ptr, size_t p_begin, size_t p_end) {
CRASH_COND(p_end <= p_begin);
_ptr = p_ptr + p_begin;
_size = p_end - p_begin;
}
inline ArraySlice(std::vector<T> &vec, size_t p_begin, size_t p_end) {
CRASH_COND(p_end <= p_begin);
CRASH_COND(p_begin >= vec.size());
CRASH_COND(p_end > vec.size()); // `>` because p_end is typically `p_begin + size`
_ptr = &vec[p_begin];
_size = p_end - p_begin;
}
template <unsigned int N>
inline ArraySlice(FixedArray<T, N> &a) {
_ptr = a.data();
_size = a.size();
}
template <typename U>
ArraySlice<U> reinterpret_cast_to() const {
const size_t size_in_bytes = _size * sizeof(T);
#ifdef DEBUG_ENABLED
CRASH_COND(size_in_bytes % sizeof(U) != 0);
#endif
return ArraySlice<U>((U *)_ptr, 0, size_in_bytes / sizeof(U));
}
inline T &operator[](size_t i) {
#ifdef DEBUG_ENABLED
CRASH_COND(i >= _size);
#endif
return _ptr[i];
}
inline const T &operator[](size_t i) const {
#ifdef DEBUG_ENABLED
CRASH_COND(i >= _size);
#endif
return _ptr[i];
}
inline size_t size() const {
return _size;
}
inline T *data() {
return _ptr;
}
inline const T *data() const {
return _ptr;
}
private:
T *_ptr;
size_t _size;
};
#endif // ARRAY_SLICE_H