Types of Pointers

Passing pointer-to-enum to pointer-to-int output parameter. ... assign through the pointer. ... reason to believe that the underlying type of the enum is int, ...

Then what probably happens in printf("*p = %f \n q = %f, p = %p, &q = %p \n",*p,q,p,&q); is that the putative int *p is passed in a general purpose register, the double (the promoted value of q) is passed in a floating point register, the two pointers again in general purpose registers.

All fundamental integral types, along with all their aliases (like those in cstdint), are considered integral types by this class, including their const and volatile qualified variants. Enums are not considered integral types in C++ (see is_enum).

Like any variable or constant, you must declare a pointer before using it to store any variable address. The general form of a pointer variable declaration is − type *var-name; Here, type is the pointer's base type; it must be a valid C data type and var-name is the name of the pointer variable.

A pointer which does not have any address assigned to it is called a wild pointer. Any attempt to use such uninitialized pointers can cause unexpected behavior, either because the initial value is not a valid address, or because using it may damage other parts of the program.

You must dereference the pointer to obtain the value of the bool itself. Since you have a pointer, it will contain an address which is an integer. Since in C and C++ all non zero integers are true, you will get true.

char* and char[] are different types, but it's not immediately apparent in all cases. This is because arrays decay into pointers, meaning that if an expression of type char[] is provided where one of type char* is expected, the compiler automatically converts the array into a pointer to its first element.

Decimal point definition is - a period, centered dot, or in some countries a comma at the left of a proper decimal fraction (such as .678) or between the parts of a mixed number (such as 3.678) expressed by a whole number and a decimal fraction.