[Boost-users] [lambda] problem with if_then_else_return

From: Zeljko Vrba (zvrba_at_[hidden])
Date: 2007-12-27 04:36:11

I have a problem with the following statement:

        return std::accumulate(
                qrun_.begin(), qrun_.end(), svt,
                _1 < if_then_else_return(
                        _2 != (acct*)0,
                        bind(&acct::get_avt, _2),
                        (unsigned)-1));

Basically, I want to find the minimal value of get_avt() over all
non-null members of qrun_ which is declared as std::vector<acct*>.

I get the following compiler error with SunCC 5.9:

Error, badbinaryop: The operation
"unsigned<const boost::lambda::detail::return_type_deduction_failure<
boost::lambda::detail::return_type_2_ifthenelsereturn<1, 1, 1, 0,
unsigned, const unsigned>>" is illegal.

The get_avt method is declared as: unsigned get_avt() const
Removing the const qualifier doesn't help.

Replacing (unsigned)-1 with _1 generates the same error, but with "const
unsigned" replaced by "unsigned&".

Replacing (unsigned)-1 with bare 0 compiles without any error, but does
not compute what I want.

Any suggestions about what am I doing wrong?