0 day streak
cpp / expert
Snippet

Explicit Memory Layouts in Buffers

Low-level memory management using placement new and manual destructor calls. This technique is essential for building custom containers or handling objects in pre-allocated memory pools with strict alignment requirements.

snippet.cpp
cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
template <typename T>
struct ManualStorage {
alignas(T) std::byte buffer[sizeof(T)];
bool initialized = false;
template <typename... Args>
void construct(Args&&... args) {
new (buffer) T(std::forward<Args>(args)...);
initialized = true;
}
void destroy() {
if (initialized) {
reinterpret_cast<T*>(buffer)->~T();
initialized = false;
}
}
T* get() { return reinterpret_cast<T*>(buffer); }
};
Breakdown
1
alignas(T) std::byte buffer[sizeof(T)];
Ensures the raw byte array is properly aligned in memory for the specific type T.
2
new (buffer) T(std::forward<Args>(args)...);
Placement new: constructs an object of type T directly into the provided memory address.