Comments on: 4.4 — Type conversion and casting

By: SamHocevar

SamHocevar — Sat, 28 Jan 2012 14:40:08 +0000

I mean “” provides fmod. The blog engine ate my tags and there is no preview.

By: SamHocevar

SamHocevar — Sat, 28 Jan 2012 14:39:09 +0000

That is not really true. The % operator cannot be used with doubles, but provides double fmod(double x, double y) which is modulus for doubles.

By: SamHocevar

SamHocevar — Sat, 28 Jan 2012 14:28:37 +0000

I would like to point out that “int nValue = 10 * 2.7″ does not really work “as expected”. It is not possible to store the value 2.7 in a double. Instead, the value stored in the machine register is something like 2.7000000000000001776… (continuing to 51 digits). You are lucky that the IEEE rounding rules allow the computation to give 27 at the end, but in general you should never expect a floating-point computation on inexact values to give an exact result.

The value 2.5 can be represented exactly as a double, however. So you are guaranteed that 10 * 2.5 will be 25.

By: Function overloading « Learn C++ Programming

Function overloading « Learn C++ Programming — Mon, 16 Jan 2012 09:43:14 +0000

[...] If no exact match is found, C++ tries to find a match through promotion. In the lesson on type conversion and casting, we covered how certain types can be automatically promoted via internal type conversion to other [...]

By: zingmars

zingmars — Tue, 19 Jul 2011 11:05:01 +0000

was using static_cast ever safe? :p

By: Konda

Konda — Sat, 16 Jul 2011 11:42:29 +0000

Wait sorry about that, the “int” in the angled brackets after “static_cast” seems to disappear.

By: Konda

Konda — Sat, 16 Jul 2011 11:41:15 +0000

static_cast([float value here])

fixed

By: Konda

Konda — Sat, 16 Jul 2011 11:40:11 +0000

Hello, I have a question: Is it safe to use static_cast([float value here]) to truncate a float value? And no, I’m not talking about rounding.

By: surya

surya — Wed, 22 Jun 2011 04:42:32 +0000

thank you zingmars

By: zingmars

zingmars — Tue, 21 Jun 2011 15:17:27 +0000

This is what compiler does too – it does whatever you ask from it, and assigns the results to a memory location, and then you store it in p1.
And no – the line does not work. Firstly because apparently you can’t do static cast on pointers (they’re memory locations, not values or types or anything).
Also – one does not simply convert one class to another. It doesn’t work that way.
Just my 2 cents.
So I guess the answer to the ‘what does it hold’ is – nothing. It holds nothing because you can’t do things this way.