On 19.02.2011 13:06, spir wrote:
Hello,What do you think of this? unittest { assert(-1.1 + 2.2 == 1.1); // pass assert(-1.1 + 2.2 + 3.3 == 4.4); // pass assert(-1.1 + 3.3 + 2.2 == 4.4); // fail assert(-1.1 + 3.3 == 2.2); // fail } There is approxEquals in stdlib, right; but shouldn't builtin "==" be consistent anyway? Denis
It is generally a bad idea to use "==" with floats, as most decimals cant be represented exact in binary floating point. That means there is no float for the value "1.1". Though there are exact floats for 0.25, 0.5, 42.125 and so on. The only reason the first two testcases work is, that it is rounded the same way both sides of the "==" but you should not rely on that.
Also note, that these calculations are probably done at compile-time, and the compiler is allowed to use a higher precision than at run-time, so you might get different result when you let the user input the numbers.
- Krox
