Just figured out we can do this. Could this be added to phobos?
----
//in std.compiler (or std.traits?)
template Version(alias V){
mixin(`
version(`~V~`){
enum Version=true;
}
else
enum Version=false;
`);
}
----
usage:
----
import std.compiler;
void main(){
static if(!Version!"assert")
writeln("not assert");
static if(Version!"OSX" && !Version!"D_NoBoundsChecks" || !Version!"assert")
{
writeln("special code");
}
}
----
without this, we have to resort to something ugly, not dry, error prone:
----
//pollutes namespace, as we can't define version=temp inside a function
version(OSX)
{
version(D_NoBoundsChecks)
{
}
else
{
version=temp;//need to make sure temp doesn't clash with other version identifiers / symbols
}
}
else
{
version(assert)
{
}
else
{
version=temp;//NOT DRY: repeats temp
}
}
void main()
{
version(assert)
{
}
else
{
writeln("not assert");
}
version(temp) // here we use it
{
writeln("special code");
}
}
----
Likewise, with debug:
----
template Debug(alias V){
import std.traits:isIntegral;
static if(!isIntegral!(typeof(V))){
mixin(`
debug(`~V~`){
enum Debug=true;
}
else
enum Debug=false;
`);
}
else{
import std.conv:to;
mixin(`
debug(`~V.to!string~`){
enum Debug=true;
}
else
enum Debug=false;
`);
/+
//NOTE:maybe a dmd bug but this didn't work
debug(V)
enum Debug=true;
else
enum Debug=false;
+/
}
}
----
usage:
----
void main(){
import std.compiler;
static if(Debug!2){
writeln("debug>=2");
}
static if(Debug!"foo"){
writeln("debug=foo");
}
}