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On Saturday, 14 August 2021 at 23:09:14 UTC, Paul Backus wrote:
>On Saturday, 14 August 2021 at 14:04:47 UTC, kdevel wrote:
> char [7] d7 = "x"; // okay
string s = "x";
char [7] c7 = s; // throws RangeError
What justifies that the compiler behaves differently on two terms ('s', '"x"') which are of equal size, type, length and value?
Literals in D can have different types in different contexts. For example:
byte b = 16; // 16 is treated as a byte literal
int n = 16; // 16 is treated as an int literal
b = n; // Error: cannot convert int to byte
The wording of the error message
void main () // bi.d
{
byte b = 257;
}
$ dmd bi.d
bi.d(3): Error: cannot implicitly convert expression `257` of type `int` to `byte`
does not seem to support your interpretation. The term 257 does not encode a ‘polymorphic’ entity but the int value 257 which is used to initialize a variable. If necessary, the value is converted. The literal is not “typeless” as in Go [1] either.
Similarly, the string literal "x" can be treated either as a string (a dynamic array of immutable(char)) or as a static array of char, depending on the type of variable it's assigned to.