Re: Template variable not reach at compile
On Saturday, 21 July 2018 at 13:13:11 UTC, Mike Parker wrote:
On Saturday, 21 July 2018 at 12:17:54 UTC, Greatsam4sure wrote:
Sorry for the typo. This is the problem
auto arithmetic(T, V, U)(T a, V b, U op){
return mixin("a"~op~"b");
}
//call like this
arithmetic(1.5,2.5,"+");
Compiler says the variable op is not reach at compile time.
So how can the varible a and b be reach at compile time and op
is not reach. I will appreciate any help. I have also use a
static if but the same complain. Just a newbie in D
You aren't using a or b at compile time -- you're using the
string literals "a" and "b", which have nothing at all to do
with a and b. In order to get what you want, you need to make
op a template parameter like this:
auto arithmetic(string op, T, V)(T a, V b)
{
mixin("a"~op~"b");
}
arithmetic!("+")(1.5, 2.5);
Thanks Sir. Really appreciate your reply it works for me. I also
want to thank you for all your labour in the dlang ecosystem or
foundation. I read about the dlang announce group every day. I
will also want update to dlang this week or close it down or
redirect to the announce group directly
Re: Template variable not reach at compile
On Saturday, 21 July 2018 at 12:17:54 UTC, Greatsam4sure wrote:
Sorry for the typo. This is the problem
auto arithmetic(T, V, U)(T a, V b, U op){
return mixin("a"~op~"b");
}
//call like this
arithmetic(1.5,2.5,"+");
Compiler says the variable op is not reach at compile time. So
how can the varible a and b be reach at compile time and op is
not reach. I will appreciate any help. I have also use a static
if but the same complain. Just a newbie in D
You aren't using a or b at compile time -- you're using the
string literals "a" and "b", which have nothing at all to do with
a and b. In order to get what you want, you need to make op a
template parameter like this:
auto arithmetic(string op, T, V)(T a, V b)
{
mixin("a"~op~"b");
}
arithmetic!("+")(1.5, 2.5);
Re: Template variable not reach at compile
On 22/07/2018 12:15 AM, Greatsam4sure wrote:
auto arithmetic(T, V, U)(T a, V b, U op){
return mixin("a"~op~"b");
}
//call like this
arithmetic(1.5,2.5,"op");
Compiler says the variable op is not reach at compile time. So how can
the varible a and b be reach at compile time and op is not reach. I will
appreciate any help. I have also use a static if but the same complain.
Just a newbie in D
Simple, it was never requested to be reached.
The correct code is:
auto arithmetic(string op, T, V)(T a, V b) {
return mixin("a" ~ op ~ "b");
}
arithmetic!("op")(1.5, 2.5);
D is not dynamic, if you need access to compile time features like
string mixin, you must pass them via the template parameters. You can't
use regular old variables to do this, as the code hasn't even been
generated yet.
Template variable not reach at compile
Sorry for the typo. This is the problem
auto arithmetic(T, V, U)(T a, V b, U op){
return mixin("a"~op~"b");
}
//call like this
arithmetic(1.5,2.5,"+");
Compiler says the variable op is not reach at compile time. So
how can the varible a and b be reach at compile time and op is
not reach. I will appreciate any help. I have also use a static
if but the same complain. Just a newbie in D
Template variable not reach at compile
auto arithmetic(T, V, U)(T a, V b, U op){
return mixin("a"~op~"b");
}
//call like this
arithmetic(1.5,2.5,"op");
Compiler says the variable op is not reach at compile time. So
how can the varible a and b be reach at compile time and op is
not reach. I will appreciate any help. I have also use a static
if but the same complain. Just a newbie in D
