Question

What is the correct type to use in Qt development (or C++ in general) for decimal arithmetic, i.e. the equivalent of System.Decimal struct in .Net?

• Does Qt provide a built-in struct? (I can’t find it in the docs, but maybe don’t know where to look.)
• Is there a “standard” C++ library to use?

Answer 1

What is the correct type to use in Qt
development (or C++ in general) for
decimal arithmetic, i.e. the
equivalent of System.Decimal struct in
.Net?

Neither C++ standard library nor Qt has any data type equivalent to System.Decimal in .NET.

Does Qt provide a built-in struct? (I
can’t find it in the docs, but maybe
don’t know where to look.)

No.

Is there a “standard” C++ library to
use?

No.

But you might want to have a look at the GNU Multiple Precision Arithmetic Library.

[EDIT:] A better choice than the above library might be qdecimal. It wraps an IEEE-compliant decimal float, which is very similar (but not exactly the same as) the .NET decimal, as well utilizing Qt idioms and practices.