initialization - What are primitive types default-initialized to in C++? -

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when use initialization list:

struct struct {     struct() : membervariable() {}     int membervariable; };

the primitive type (int, bool, float, enum, pointer) member variable default-initialied. value gets implementation defined or same implementations?

you not correct. object not default-initialized value-initialized. , value well-defined

int = 0,  bool = false,  float = 0.0f,   enum = (enum type)0,  pointer = null pointer pointer member = null member pointer

note 0 in range of values enumeration, if doesn't contain explicit enumerator vaue, it's safe initialize enumeration variable value.

in particular pointer data members, representation used in practice not all-zero bits. in so-called c++ itanium abi used @ least gcc , clang, pointer data members have all-one bits null representation.


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