Hi,
Recently, I was trying to solve some funny coding challenges
(https://www.techgig.com).
The questions were really simple, but I found it interesting
because the website allows to use D.
One of the task was to take a string from STDIN and detect its
type.
There were a few options: Float, Integer, string and "something
else" (which, I think, doesn't have any sense under the scope of
the task).
Anyway, I was struggling to find a built-in function to
distinguish float and integer types from a string.
I came to the following solution:
```
import std.stdio;
import std.range;
import std.conv;
import std.string;
import std.format;
immutable msg = "This input is of type %s";
void main()
{
string type;
auto data = stdin.byLine.takeOne.front;
if (data.isNumeric) {
type = data.indexOf(".") >= 0 ? "Float" : "Integer";
}
else {
type = "string";
}
writeln(msg.format(type));
}
```
But I think that's ugly. The thing is that in PHP, for example, I
would do that like this:
```
if (is_integer($data)) {
//...do smth
}
else if (is_float($data)) {
//...do smth
}
else {
//...do smth
}
```
I tried to use std.conv.to and std.conv.parse, but found that
they can't really do this. When I call `data.to!int`, the value
of "123.45" will be converted to int!
Is there any built-in way to detect these types?
Thanks!
