C++ Coding Standards: 101 Rules, Guidelines, and Best Practices

13. Ensure resources are owned by objects. Use explicit RAII and smart pointers

Summary

Don’t saw by hand when you have power tools: C++’s “resource acquisition is initialization” (RAII) idiom is the power tool for correct resource handling. RAII allows the compiler to provide strong and automated guarantees that in other languages require fragile hand-coded idioms. When allocating a raw resource, immediately pass it to an owning object. Never allocate more than one resource in a single statement.

Discussion

C++’s language-enforced constructor/destructor symmetry mirrors the symmetry inherent in resource acquire/release function pairs such as fopen/fclose, lock/unlock, and new/delete. This makes a stack-based (or reference-counted) object ...