C & C++

An inheriting class with a user-defined copy constructor must call its base class's copy constructor.

Fall-through in switch cases is often considered risky. Hence consider adding an unconditional break for each switch clause.

The malloc function usually expects a memory size value in units (usually byte) when allocating any type. Use sizeof(type) * number_of_values as the size argument for malloc to avoid making mistakes.

Calling math functions that only accept double with float arguments causes an implicit type promotion of float argument. Type promoting float to double costs extra space in memory, it also costs extra instructions for the conversion from float and lastly vectorisation of float is a lot more efficient compared to double.

Pointer offset(or any other arithmetic operation) on a pointer casted to a different type (than its original type) is risky and can result in undefined behaviour. The reason for such behaviour is that the memory alignment may change for types on every targeted platform.