CODEWITHSUNDEEP
c++syntaxreference
Vaelus
Vaelus

Reputation: 1065

C++ Reference Variable Declaration Syntax Reasoning

All other declaration syntaxes in C++ make a lot of sense, for examples:

int i;

i is an int 

int *i;

when i is dereferenced, the result is an int 

int i[];

when i is subscripted, the result is and int 

int *i[];

when i is subscriped, then the result is derefrenced, the final result is an int

But when you look at the syntax for reference variables, this otherwise consistent reasoning falls apart.

int &i = x;

“when the address of i is taken, the result is an int” makes no sense.

Am I missing something, or is this truly an exception to the apparent reasoning behind the other sytaxes? If it is an exception, why was this syntax chosen?

Edit:

This question addresses why the & symbol may have been chosen for this purpose, but not whether or not there is a universally consistent way to read declarations different from the way described above.

Upvotes: 1

Views: 167

Answers (1)

Brian Bi
Brian Bi

Reputation: 119164

Once bound, a reference becomes an alias for its referent, and cannot be distinguished from it (except by decltype). Since int& is used exactly as int is, a declaration-follows-usage syntax could not work for declaring references.

The syntax for declaring references is pretty straightforward, still. Just write down a declaration for the corresponding pointer type, then replace the * used for the initial dereference by & or &&.

Upvotes: 5

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