• Evan Davis (25/25) Jun 06 2014 Hello,
• Chris Nicholson-Sauls (3/28) Jun 06 2014 Is there any reason you couldn't (or would rather not) use
• Evan Davis (6/8) Jun 06 2014 That would work. What would be the best way to auto-generate the
• Philippe Sigaud via Digitalmars-d-learn (21/27) Jun 06 2014 Maybe you could use a struct template, with UDP as a template

"Evan Davis" <cptroot gmail.com> writes:

Hello,

I'm looking to use the Tuple type as a way of generating types to 
represent data in a send recieve connection pair. I created a 
template to try this:


template s_to_c(UDP packetType) {
          static if (packetType == UDP.ping) {
     alias Tuple!() s_to_c;
   } else static if (packetType == UDP.connect) {
     alias Tuple!(byte) s_to_c;
   } else static if (packetType == UDP.keep_alive) {
     alias Tuple!() s_to_c;
   }
}

(UDP is a enum with packet types.)

This works, but it also means that s_to_c(UDP.ping) is the same 
type as s_to_c(UDP.keep_alive). I want to be forced to 
distinguish between types, even if they contain the same fields, 
so that

recieve(
   (s_to_c!(UDP.ping) value) { },
   (s_to_c!(UDP.keep_alive) value) { }
)

isn't an error.

Any suggestions are welcome, and thanks for any help,

-Evan Davis

"Chris Nicholson-Sauls" <ibisbasenji gmail.com> writes:

On Friday, 6 June 2014 at 23:44:04 UTC, Evan Davis wrote:
 Hello,

 I'm looking to use the Tuple type as a way of generating types 
 to represent data in a send recieve connection pair. I created 
 a template to try this:


 template s_to_c(UDP packetType) {
          static if (packetType == UDP.ping) {
     alias Tuple!() s_to_c;
   } else static if (packetType == UDP.connect) {
     alias Tuple!(byte) s_to_c;
   } else static if (packetType == UDP.keep_alive) {
     alias Tuple!() s_to_c;
   }
 }

 (UDP is a enum with packet types.)

 This works, but it also means that s_to_c(UDP.ping) is the same 
 type as s_to_c(UDP.keep_alive). I want to be forced to 
 distinguish between types, even if they contain the same 
 fields, so that

 recieve(
   (s_to_c!(UDP.ping) value) { },
   (s_to_c!(UDP.keep_alive) value) { }
 )

 isn't an error.

 Any suggestions are welcome, and thanks for any help,

 -Evan Davis


Is there any reason you couldn't (or would rather not) use 
structs rather than tuples?

"Evan Davis" <cptroot gmail.com> writes:

On Saturday, 7 June 2014 at 03:14:52 UTC, Chris Nicholson-Sauls 
wrote:
 Is there any reason you couldn't (or would rather not) use 
 structs rather than tuples?

That would work. What would be the best way to auto-generate the 
types? I have somewhere around 30 already, and the number will 
grow with this project.

Evan Davis

Philippe Sigaud via Digitalmars-d-learn writes:

 Is there any reason you couldn't (or would rather not) use structs rather
 than tuples?


 That would work. What would be the best way to auto-generate the types? I
 have somewhere around 30 already, and the number will grow with this
 project.

 Evan Davis

Maybe you could use a struct template, with UDP as a template
parameter. It'll instantiate a different type for each UDP value. If
you add new possible values to the enum, the rest of the code will
follow.

struct SendReceivePair(UDP udp)
{
    /// maybe here some different values, differentiated by static if,
if needed.
}

Then, use these types directly in 'receive':

receive(
  (SendReceivePair!(UDP.ping) value) { },
  (SendReceivePair!(UDP.keep_alive) value) { }
)

If you want to 'retrieve' the UDP template parameter, you can expose
it through an alias:


struct SendReceivePair(UDP udp)
{
    alias packetType = udp;
}

So, given SendReceivePair!(xxx) srp, you can get 'xxx' by srp.packetType;