Query related with the constant storage

[isaisa]

Hi
I have one basic query regarding how the system stores the Constants.

If i have the following code

double &dr = 1 ; // error: lvalue needed
constdouble &cdr = 1 ;

As the comment suggest, the lvalue required fot the plain reference but not for the const double&. Is there any specific reason for this in the context of storage of normal variable v/s constants ? I am little confussed on this.

Thanks in advance.

sanjay

 

[ArkM]

You want to initialize a reference to the (constant!) 1 (one). Well, you may get a constant reference to a constant (the language creates implicit variable with value 1, line #2), but you can't create a normal reference with read/write access rights (line #1). It's (reasonable) C++ rules.

If it's possible, a compiler places all constants in read-only pages/segments, but it's another story. Probably, you want symbolic named constant (double one = 1), not a reference to constant?