👀 Views: 36 💬 Answers: 1 📅 Created: 2025-06-07

c++17 std-string-view custom-allocator cpp

I'm not sure how to approach Does anyone know how to I'm working with an scenario with comparing a `std::string_view` to a `std::string` when using custom allocators in C++17... I expected the comparison to work seamlessly, but I keep getting unexpected results. Here's a simplified version of my code: ```cpp #include <iostream> #include <string> #include <string_view> #include <memory> class CustomAllocator { /* Custom allocator implementation */ }; int main() { std::string s("Hello, World!"); std::string_view sv(s.c_str()); // Comparison that fails unexpectedly if (sv == s) { std::cout << "Equal!" << std::endl; } else { std::cout << "Not Equal!" << std::endl; } return 0; } ``` When I run this code, it prints "Not Equal!" even though I would expect "Equal!". I've checked the contents of both `sv` and `s`, and they seem to match perfectly. I also tried using `sv.compare(s)` and that also returned a non-zero value. I suspect the scenario might be related to how the string is being allocated or the way `std::string_view` interacts with custom allocators, but I need to seem to find any documentation that mentions this behavior. I've tried running the code with a standard allocator and the comparison works as expected. Has anyone else encountered this scenario or can provide insight on how to properly compare `std::string_view` with `std::string` when using custom allocators? I'm using g++ version 9.3.0 on Ubuntu 20.04. Any guidance would be greatly appreciated! My development environment is Windows 10. Any feedback is welcome! Any suggestions would be helpful.