About assembly instructions: NEG How to operate with c\c++

If the assembly is:

NEG EAX;

So, what if we implement it in C or C + +? Can be used: Value=~value to achieve it?

Neg I began to think that the reverse, the result is always wrong, the last 1 less.

Later view neg's explanation, called to fill.

A complement? Positive values are unchanged, negative values are reversed plus the implementation?

Later, I use Value=-value directly, the result is correct!!

It seems that the meaning of take-up is to take negative, if you use C or C + + to achieve, you can directly take the negative, rather than the meaning of the reverse position ...

About assembly instructions: NEG How to operate with c\c++