#macro and #if

[Schrubber]

Hello,

Why does this not go?

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#macro machwas(DTYPE, D)

#if typeof(DTYPE) = typeof(single)
    cast(single, D)
#endif

#endmacro

    dim as double cr = 0.0045
    dim as single e

    e = machwas(single, cr)

Thanks
Schrubber

[SARG]

#if and so on are to be used with the preprocessor not for your code.

You should use if and endif but think that the macro is replaced by all its lines giving a strange statement and obviously errors....

Why not simply write ?

Code: Select all

e = cast(single, cr)

[Schrubber]

Hello,

these were only one simplistic examples.

Code: Select all

#macro machwas(DTYPE, D)

#if typeof(DTYPE) = typeof(DOUBLE)
  iif(abs(cast(DTYPE, iif(cast(DTYPE, D) >= 0, cast(DTYPE, D), cast(DTYPE, -D)))) <= 0.000000000001, true, false)
#elseif typeof(DTYPE) = typeof(SINGLE)
  iif(abs(cast(DTYPE, iif(cast(DTYPE, D) >= 0, cast(DTYPE, D), cast(DTYPE, -D)))) <= 0.00001f, true, false)
#endif

#endmacro

this is what lies behind.

Thanks

[counting_pine]

It doesn't work because the #if's are evaluated when the macros are expanded, and preprocessor directives can't come in the middle of the line.
Your macro is expanded as something like:

Code: Select all

e =
#if typeof(single) = typeof(single)
    cast(single, D)
#endif

One workaround is to build the assignment into the macro:

Code: Select all

#macro machwas(e, DTYPE, D)

#if typeof(DTYPE) = typeof(single)
    e = cast(single, D)
#endif

#endmacro

    dim as double cr = 0.0045
    dim as single e

    machwas(e, single, cr)

[Schrubber]

Hy,

thanks @SARG, @counting_pine

I will implement the junk as a function.

Gruß
Schrubber