Re: [Boost-users] [Range.Ex / String.Algo] Ambiguous call to overload function "find"

Subject: Re: [Boost-users] [Range.Ex / String.Algo] Ambiguous call to overload function "find"
From: Neil Groves (neil_at_[hidden])
Date: 2009-07-05 07:04:05

2009/7/3 S.C. Leung <shaochiliang_at_[hidden]>

> Hi!
> I have downloaded Range.Ex uploaded at 26.04.2009 09:09. It seems the
> difficulties are still there.
>

The exact program you posted compiles without errors or warnings on Visual
C++ 9. I installed Boost 1.39 and then copied over the RangeEx files.

[...]

> 009/7/3 Neil Groves <neil_at_[hidden]>
>
>> Hello!
>>
>> On Fri, Jul 3, 2009 at 2:38 AM, ÁºÉÜ³Ø <shaochiliang_at_[hidden]> wrote:
>>
>>> I use vc 9.0 to compile the following code with boost 1.39.0 and
>>> range_ex.
>>>     #include<string>
>>>     #include<boost/algorithm/string.hpp>
>>>     #include<boost/range/algorithm.hpp>
>>>
>>>     int main() {
>>>         std::string s = "hello";
>>>         boost::find_first(s, "lo");
>>>         return 0;
>>>     }
>>>
>> The compiler will complain ambiguous call to overload function "find". I
>>> found there's also a "find" in boost/range/algorithm.hpp. Even worse when I
>>> change the type of "s" to const std::string, the compiler will resolute
>>> "find" call as the one in boost/range/algorithm.hpp
>>> and reports an error "const_iterator is not a member of
>>> std::_String_const_iterator". Now I just indicated the "find" call in
>>> boost::find_first explicitly. Is there a better way to solve it?
>>>
>>

This code compiles cleanly for me. I noticed that you are talking about
"find" rather than "find_first" so I took the liberty of replacing the
"find_first" with "find". This indeed produced a compiler error similar to
the one you describe. However boost::find(s, "lo") does not match the
boost/algorithm/string.hpp version because the second parameter should be a
"Finder object used for searching". Please see:
http://www.boost.org/doc/libs/1_39_0/doc/html/string_algo/reference.html#header.boost.algorithm.string.find_hpp

It also does not match the RangeEx version because "find" is used to find an
element, as opposed to a sub-sequence, from a range. Therefore I conclude
that either, I have guessed the code snippet that causes the problem
inaccurately, or that the code that produced the compiler error was simply
incorrect.

If I have guessed the code wrongly, would you please supply the exact code
that reproduces the problem. I suspect that find_first is exactly the right
solution. Please let me know either way.

 [...]

Regards,
Neil Groves