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digitalmars.D - Converting from C

reply =?ISO-8859-1?Q?Julio_C=E9sar_Carrascal_Urquijo?= writes:
How do I convert this C declaration to D:

union FloatIEEE754
{
     float floatValue;
     struct
     {
         unsigned int mantissa : 23;
         unsigned int exponent : 8;
         unsigned int sign : 1;
     } mpn;
};



-- 
Julio César Carrascal Urquijo
http://jcesar.f2o.org/
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Jun 04 2004
parent Kevin Bealer <Kevin_member pathlink.com> writes:
In article <c9q9ns$14mm$1 digitaldaemon.com>,
=?ISO-8859-1?Q?Julio_C=E9sar_Carrascal_Urquijo?= says...

How do I convert this C declaration to D:

union FloatIEEE754
{
     float floatValue;
     struct
     {
         unsigned int mantissa : 23;
         unsigned int exponent : 8;
         unsigned int sign : 1;
     } mpn;
};



Maybe like this:

struct FloatIEEE754 {

float floatValue;

int as_uint()
{
return * cast(uint*) (& floatValue);
}

uint sign()
{
return as_uint >>> 31;
}
uint exponent()
{
return as_uint << 1 >> 24;
}
uint mantissa()
{
return as_uint << 9 >>> 9;
}
}

This will allow:

struct FloatIEEE754 x;
x.floatValue = 1.123;

int a = x.sign;
int b = x.exponent;
int c = x.mantissa;

I don't remember how C++ bitfields or IEEE floats are packed, so you may need to
reverse the shifts.

Kevin
Jun 04 2004