How can I reverse a predicate's return value, and remove the elements that return false instead of true?
Here is my code:
headerList.remove_if(FindName(name));
(please ignore lack of erase)
with FindName a simple functor:
struct FindName
{
CString m_NameToFind;
FindInspectionNames(const CString &nameToFind)
{
m_NameToFind = nameToFind;
}
bool operator()(const CHeader &header)
{
if(header.Name == m_NameToFind)
{
return true;
}
return false;
}
};
I would like somethin开发者_如何学Cg like:
list.remove_if(FindName(name) == false);
Not yet using c++0x, so lambdas not allowed, sadly. I'm hoping there is a nicer solution than writing a NotFindName functor.
Check not1
in the <functional>
header:
headerList.remove_if( std::not1( FindName( name ) ) );
Oh, and this:
if(header.Name == m_NameToFind)
{
return true;
}
return false;
Please don't do that.
return ( header.Name == m_NameToFind );
That's much better, isn't it?
alternatively you could use boost bind so you don't have to write that unary_function struct:
bool header_has_name (const CHeader& h, const CString& n) {return h.name == n;}
headerList.remove_if (boost::bind (header_has_name, _1, "name"));
and for remove_if_not:
headerList.remove_if (!boost::bind (header_has_name, _1, "name"));
You could even use std::equal() to avoid the header_has_name function completely but at that point it becomes a little bit ugly.
Unfortunately I think writing a NotFindName functor is your best bet.
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