Re: Undefined reference - built from source DMD
On Wednesday, 11 September 2019 at 02:09:42 UTC, Stefanos Baziotis wrote: I have branched to an old PR (4 months ago) and the problem doesn't exist. For clarification, the problem doesn't exist _in that_ branch. On my current new branch, I still haven't been able to solve it.
Re: Blog Post #69: TextView and TextBuffer Basics
On Wednesday, 11 September 2019 at 03:45:23 UTC, Zekereth wrote: Yes, thank you very much. Your tutorials are a great help! Keep it up! Thanks again. Oakey dokey.
Re: default values depending on type of template variable
On Wednesday, 11 September 2019 at 09:05:47 UTC, Ali Çehreli wrote: Like this? Yet an other template! That's great! :-)
Re: default values depending on type of template variable
On 09/11/2019 01:35 AM, berni wrote:
I'd like to write a template, that takes a different default value
depending on the type of a variable.
Like this?
import std.stdio;
void main()
{
double a = 1e-8;
double b = 1e-10;
float c = 1e-4;
float d = 1e-6;
assert(!test(a));
assert(test(b));
assert(!test(c));
assert(test(d));
}
template DefaultFor(T) {
static if (is (T == float)) {
enum DefaultFor = 1e-5;
} else static if (is (T == double)) {
enum DefaultFor = 1e-9;
} else {
import std.string;
static assert (false, format!"%s not supported"(T.stringof));
}
}
auto test(T, U)(T value, U limit=DefaultFor!T)
{
writefln!"%s: %s(%s)"(T.stringof, U.stringof, limit);
return value
Re: default values depending on type of template variable
On Wednesday, 11 September 2019 at 08:35:02 UTC, berni wrote:
I'd like to write a template, that takes a different default
value depending on the type of a variable. I tried this, but it
doesn't work:
void main()
{
double a = 1e-8;
double b = 1e-10;
float c = 1e-4;
float d = 1e-6;
assert(!test(a));
assert(test(b));
assert(!test(c));
assert(test(d));
}
auto test(T, U)(T value, U limit=1e-9)
{
return value
Although being called with a double in the first two tests, the
second overload is always used and therefore the first test
fails. And without this overload, the last test obviously
doesn't pass.
Is there a way, to provide default values for template
parameters depending on the type of an other parameter?
unittest
{
double a = 1e-8;
double b = 1e-10;
float c = 1e-4;
float d = 1e-6;
assert(!test(a));
assert(test(b));
assert(!test(c));
assert(test(d));
}
auto test(T, U)(T value, U limit = limit!T) {
return value < limit;
}
// Solution 1:
template limit(T) {
static if (is(T == float)) {
enum limit = 1e-5;
} else {
enum limit = 1e-9;
}
}
// Solution 2:
enum limit(T : float) = 1e-5;
enum limit(T : double) = 1e-9;
With some tricks this can also be inlined:
enum If(bool b, T...) = T[b ? 0 : 1];
auto test(T, U)(T value, U limit = If!(is(T == float), 1e-5,
1e-9)) {
return value < limit;
}
--
Simen
default values depending on type of template variable
I'd like to write a template, that takes a different default
value depending on the type of a variable. I tried this, but it
doesn't work:
void main()
{
double a = 1e-8;
double b = 1e-10;
float c = 1e-4;
float d = 1e-6;
assert(!test(a));
assert(test(b));
assert(!test(c));
assert(test(d));
}
auto test(T, U)(T value, U limit=1e-9)
{
return value
Although being called with a double in the first two tests, the
second overload is always used and therefore the first test
fails. And without this overload, the last test obviously doesn't
pass.
Is there a way, to provide default values for template parameters
depending on the type of an other parameter?
