Re: [Boost-users] error using lambdas: conversion from 'x' tonon-scalar type 'y'

From: Peter Dimov (pdimov_at_[hidden])
Date: 2006-07-04 13:40:37

klaus triendl wrote:
> Peter Dimov wrote:

>> Lambda sees that you are invoking operator<< on a MySubStream& and
>> deduces the return type to be MySubStream&; it isn't smart enough to
>> see that you're actually using the operator<< definition for the
>> base class MyStream.
>
> I thought that it would be converted implicitly in the end by the
> compiler..

There is no implicit conversion from MyStream& to MySubStream&.

> Can I make it smart enough?

I showed you one way. Another would be to use ret<MyStream&> to force a 
specific return type:

http://www.boost.org/doc/html/lambda/le_in_details.html#lambda.overriding_deduced_return_type