Write a one-line compile-time function (or template) that returns a number, which can be written in binary as 010101010...010101. Exactly the same code should work for byte, short, int, long, cent etc.

No loops or recursion allowed. Use nothing but brain! :)

Reply to Koroskin,

> Write a one-line compile-time function (or template) that returns a
> number, which can be written in binary as 010101010...010101. Exactly
> the  same code should work for byte, short, int, long, cent etc.
> 
> No loops or recursion allowed. Use nothing but brain! :)
> 

template it(T)
{
T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
}

BCS wrote:
> Reply to Koroskin,
> 
>> Write a one-line compile-time function (or template) that returns a
>> number, which can be written in binary as 010101010...010101. Exactly
>> the  same code should work for byte, short, int, long, cent etc.
>>
>> No loops or recursion allowed. Use nothing but brain! :)
>>
> 
> template it(T)
> {
> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
> }
> 
> 
Tried something like this, but mine and yours gives integer overflow...

Wyverex wrote:
> BCS wrote:
>> Reply to Koroskin,
>>
>>> Write a one-line compile-time function (or template) that returns a
>>> number, which can be written in binary as 010101010...010101. Exactly
>>> the  same code should work for byte, short, int, long, cent etc.
>>>
>>> No loops or recursion allowed. Use nothing but brain! :)
>>>
>>
>> template it(T)
>> {
>> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
>> }
>>
>>
> Tried something like this, but mine and yours gives integer overflow...


template crazy( T )
{
  T crazy =  0xAAAA_AAAA_AAAA_AAAA;
}

as long as the hex string is less then ulong.max ...  or ucent.max when that gets implemented...

Wyverex schrieb:
> Wyverex wrote:
>> BCS wrote:
>>> Reply to Koroskin,
>>>
>>>> Write a one-line compile-time function (or template) that returns a
>>>> number, which can be written in binary as 010101010...010101. Exactly
>>>> the  same code should work for byte, short, int, long, cent etc.
>>>>
>>>> No loops or recursion allowed. Use nothing but brain! :)
>>>>
>>>
>>> template it(T)
>>> {
>>> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
>>> }
>>>
>>>
>> Tried something like this, but mine and yours gives integer overflow...
> 
> 
> template crazy( T )
> {
>   T crazy =  0xAAAA_AAAA_AAAA_AAAA;
> }
> 
> as long as the hex string is less then ulong.max ...  or ucent.max when that gets implemented...

template func( T ) { T func = mixin( "0x555555555555555555555555"[0 .. T.sizeof*2+2] ); }

On Thu, 07 Aug 2008 05:59:30 +0400, Frank Benoit <keinfarbton@googlemail.com> wrote:

> Wyverex schrieb:
>> Wyverex wrote:
>>> BCS wrote:
>>>> Reply to Koroskin,
>>>>
>>>>> Write a one-line compile-time function (or template) that returns a
>>>>> number, which can be written in binary as 010101010...010101. Exactly
>>>>> the  same code should work for byte, short, int, long, cent etc.
>>>>>
>>>>> No loops or recursion allowed. Use nothing but brain! :)
>>>>>
>>>>
>>>> template it(T)
>>>> {
>>>> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
>>>> }
>>>>
>>>>
>>> Tried something like this, but mine and yours gives integer overflow...
>>   template crazy( T )
>> {
>>   T crazy =  0xAAAA_AAAA_AAAA_AAAA;
>> }
>>  as long as the hex string is less then ulong.max ...  or ucent.max when that gets implemented...
>
> template func( T ) { T func = mixin( "0x555555555555555555555555"[0 .. T.sizeof*2+2] ); }

No-no-no. It should work for integer type of *any* length (byte, short, long, cent and any future type).
And there is a *much* simpler solution!

Koroskin Denis schrieb:
> On Thu, 07 Aug 2008 05:59:30 +0400, Frank Benoit <keinfarbton@googlemail.com> wrote:
> 
>> Wyverex schrieb:
>>> Wyverex wrote:
>>>> BCS wrote:
>>>>> Reply to Koroskin,
>>>>>
>>>>>> Write a one-line compile-time function (or template) that returns a
>>>>>> number, which can be written in binary as 010101010...010101. Exactly
>>>>>> the  same code should work for byte, short, int, long, cent etc.
>>>>>>
>>>>>> No loops or recursion allowed. Use nothing but brain! :)
>>>>>>
>>>>>
>>>>> template it(T)
>>>>> {
>>>>> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
>>>>> }
>>>>>
>>>>>
>>>> Tried something like this, but mine and yours gives integer overflow...
>>>   template crazy( T )
>>> {
>>>   T crazy =  0xAAAA_AAAA_AAAA_AAAA;
>>> }
>>>  as long as the hex string is less then ulong.max ...  or ucent.max when that gets implemented...
>>
>> template func( T ) { T func = mixin( "0x555555555555555555555555"[0 .. T.sizeof*2+2] ); }
> 
> No-no-no. It should work for integer type of *any* length (byte, short, long, cent and any future type).
> And there is a *much* simpler solution!

right.
template func( T ) { T func = T.max/3; }

On Thu, 07 Aug 2008 18:11:27 +0400, Frank Benoit <keinfarbton@googlemail.com> wrote:

> Koroskin Denis schrieb:
>> On Thu, 07 Aug 2008 05:59:30 +0400, Frank Benoit <keinfarbton@googlemail.com> wrote:
>>
>>> Wyverex schrieb:
>>>> Wyverex wrote:
>>>>> BCS wrote:
>>>>>> Reply to Koroskin,
>>>>>>
>>>>>>> Write a one-line compile-time function (or template) that returns a
>>>>>>> number, which can be written in binary as 010101010...010101. Exactly
>>>>>>> the  same code should work for byte, short, int, long, cent etc.
>>>>>>>
>>>>>>> No loops or recursion allowed. Use nothing but brain! :)
>>>>>>>
>>>>>>
>>>>>> template it(T)
>>>>>> {
>>>>>> T it = 0x5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555_5555 & (t.max | t.min);
>>>>>> }
>>>>>>
>>>>>>
>>>>> Tried something like this, but mine and yours gives integer overflow...
>>>>   template crazy( T )
>>>> {
>>>>   T crazy =  0xAAAA_AAAA_AAAA_AAAA;
>>>> }
>>>>  as long as the hex string is less then ulong.max ...  or ucent.max when that gets implemented...
>>>
>>> template func( T ) { T func = mixin( "0x555555555555555555555555"[0 .. T.sizeof*2+2] ); }
>>  No-no-no. It should work for integer type of *any* length (byte, short, long, cent and any future type).
>> And there is a *much* simpler solution!
>
> right.
> template func( T ) { T func = T.max/3; }

Doesn't work for signed types :P
But you are close!

Koroskin Denis schrieb:

>> right.
>> template func( T ) { T func = T.max/3; }
> 
> Doesn't work for signed types :P
> But you are close!

template func( T ) { T func = T.min < 0 ? T.max/3*2+1 : T.max/3; }

Reply to Frank,

> func( T ) { T func = mixin( "0x555555555555555555555555"[0 .. T.sizeof*2+2] 
); }
> 


Gaaahhh!!! My eyes <G>