Hi Guys,
Let us do a small program. Find out the maximum and minimum values of different types in C (int, unsigned int, float, double etc). The challenging part here is that the program needs to be portable. It should give the correct ranges when run either on a 32 bit or a 64 bit machine
you can start with
and post your effortCode:unsigned char maxchar = ~0;
All problems in computer science can be solved by another level of indirection,
except for the problem of too many layers of indirection.
– David J. Wheeler
limits.h should make things easy.
For integral types, see the macros defined in <limits.h>Originally Posted by swaugh
e.g. 'INT_MAX', 'INT_MIN', etc.
For real number types, see the macros in <float.h>,
e.g. 'FLT_MIN', 'FLT_MAX', etc.
That's the ONLY way your program can be fully portable. There is no portable way to find out by direct computation.
Variable underflow for unsigned types isn't portable? -1uThere is no portable way to find out by direct computation.
dwk
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It is, but I meant that there isn't any portable way for ALL the types, including the signed ones, as the OP wanted.
Sorry, I took your statement to mean all types. Whew, because I'm very fond of using (size_t)-1 rather than the C99 SIZE_MAX.It is, but I meant that there isn't any portable way for ALL the types, including the signed ones, as the OP wanted.Variable underflow for unsigned types isn't portable? -1uThere is no portable way to find out by direct computation.
What about this for integral types?
<limits.h> is definitely a better idea.Code:int x; for(x = 0; (int)(x+1) > x; x ++);
dwk
Seek and ye shall find. quaere et invenies.
"Simplicity does not precede complexity, but follows it." -- Alan Perlis
"Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
"The only real mistake is the one from which we learn nothing." -- John Powell
Other boards: DaniWeb, TPS
Unofficial Wiki FAQ: cpwiki.sf.net
My website: http://dwks.theprogrammingsite.com/
Projects: codeform, xuni, atlantis, nort, etc.
Undefined behavior for signed types.What about this for integral types?
Code:int x; for(x = 0; (int)(x+1) > x; x ++);
Quzah.
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