C++ std::vector not resizing correctly when using custom allocator
I'm migrating some code and I'm not sure how to approach I've encountered a strange issue with I'm working with an scenario with `std::vector` when using a custom allocator in my C++ project....... I'm on GCC 11.2, and my custom allocator seems to be causing problems when I try to resize the vector. Specifically, when I call `vec.resize(new_size)`, the vector does not seem to increase its capacity as expected. Instead, I get a runtime behavior stating 'std::bad_alloc'. Here's a snippet of the code: ```cpp #include <iostream> #include <vector> #include <memory> template <typename T> struct CustomAllocator { using value_type = T; CustomAllocator() = default; template <typename U> CustomAllocator(const CustomAllocator<U>&) {} T* allocate(std::size_t n) { if (n > std::size_t(-1) / sizeof(T)) throw std::bad_alloc(); return static_cast<T*>(::operator new(n * sizeof(T))); } void deallocate(T* p, std::size_t) noexcept { ::operator delete(p); } }; int main() { std::vector<int, CustomAllocator<int>> vec; vec.push_back(1); vec.resize(10); // This line causes std::bad_alloc return 0; } ``` I've confirmed that the allocation in the custom allocator works fine in isolation. The scenario arises only when the vector attempts to resize. I've also tried explicitly specifying the new capacity after resizing, but it has not resolved the scenario. Any idea what might be going wrong? There's a possibility that I'm missing something in the allocator's implementation that affects how `std::vector` manages its memory. I'm also considering if there might be some alignment issues, but I've ensured that the allocated size is correct. Has anyone encountered this scenario before or can provide insights on allocator behavior with `std::vector`? Is there a better approach? I'm developing on Windows 11 with C++. I appreciate any insights! The stack includes C++ and several other technologies. Thanks in advance! This is my first time working with C++ latest. Any ideas how to fix this? What am I doing wrong?