(offtopic: Purify and Valgrind) Re: [Coin-discuss] Purify UMR CoinFactorization::pivotOneOtherRow

[Brian Borchers]

As an example of the kind of thing I'm talking about, suppose that I have
 
static int foo;
 
and then somewhere in my code I use foo in an expression without having 
stored anything in the variable.  Valgrind can detect this, but the
version of Purify that I used some years ago couldn't.  

The basic difference here is between a malloc debugging library that
replaces the conventional malloc() and friends, allocates unwriteable
memory before and after malloc()'d blocks, etc. and a tool that
is involved in every memory reference made by the code.