retrun type

I like to know the subtle differences in the qualified expression
stg_logic_vector'(...) and type conversion function
to_std_logic_vector(...) both returning the same type.

 

[Paul Uiterlinden]

yaseenzaidi@NETZERO.com wrote:

I like to know the subtle differences in the qualified expression
stg_logic_vector'(...) and type conversion function
to_std_logic_vector(...) both returning the same type.

Qualifying is used to resolve abiguities (so no conversion takes place),
whereas type conversion really converts from one type to another.

In my experience qualifying is needed most frequently with overloaded
procedures. Example: write(l, string'("hello"));. Without the
qualifying, the type of the second argument of write is ambiguous
(string, std_logic_vector, bit_vector), because write is overloaded for
these types.

Paul.