C++ interview questions and answers

Overriding can return a pointer/reference to Derived when base returns Base.

You pass stop tokens or framework-specific cancellation into awaitables.

A technique to safely reclaim lock-free nodes readers might still see.

When no synchronization is needed beyond atomicity, like counters.

Preallocate blocks and freelist them for fixed sizes.

Deleters must match allocation method and not hide bugs from ASan.

Profile-guided optimization trains the compiler on real runs then rebuilds.

Single instruction multiple data processes vectors of values.

The end iterator.

The compiler picks the best matching function among candidates.

std::visit applies a visitor to the active alternative.

It does not own memory — dangling if the underlying string dies.

ThreadSanitizer finds many races in tests.

Hide data behind public methods with private fields.

A template that carries type information or constants for algorithms.

Allocations needing alignment beyond new’s default, like AVX types.

Combining object files and libraries into an executable or shared lib.

Called when exception handling fails, like throw from destructor during unwind.

Named modules export interfaces with fewer textual includes and better isolation.

Random access iterators and a strict weak ordering comparator.