[boost] Re: Including abs() in rational.hpp

From: jsiek_at_[hidden]
Date: 1999-12-10 18:24:02

Here's a small example that breaks with VC++ 6.0 sp3.

#include <complex>

int main(int,char*[])
{
  using std::abs;
  abs(3.0);
  return 0;
}

One of the reasons for the above problem (among several I'm sure)
is that the abs() for double, etc. are not in std for VC++. Even
so it's kind of funny that the using clause hides the abs's
in the global namespace.

And you can't just tell a user to be careful because he's not the one
writing generic algorithms with abs() in, I am. (for instance, MTL has
a generic "one_norm" function using std::accumulate that will work for
all numeric types, including double and complex)

If anyone knows of any other workarounds I'd be obliged! :)

Gabriel Dos Reis writes:
 > jsiek_at_[hidden] writes:
 > 
 > | I suppose when the compilers all get up to snuff this won't
 > | be a problem, but it currently is a headache. 
 > 
 > I suppose what is a headache is when a user writes "std::abs()"
 > assuming std::abs() is template :-) 
 > We can't fix his program (and we should not try to)
 > 
 > | ... The "using std::abs"
 > | breaks under certain conditions with a compiler from
 > | a town in the pacific northwest.
 > 
 > Does 'plain' abs() also breaks?
 > If so, there is nothing we can do for that user aprt from telling him
 > to be careful when using abs(), sorry.
 > 
 > -- Gaby
 > 
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