According to your suggestion,I tried to write: bind(static_cast<pair<IIPrimemap::iterator,bool> (*)(const IIPrimemap::value_type&)> (IIPrimemap::insert), bind(&make_pair<int,int>,_1,constant(1))); where typedef std::map<int, int> IIPrimemap; IIPrimemap primemapvec; but the complier told me that: invalid static_cast from type `<unknown type>' to type ` std::pair<std::_Rb_tree_iterator<std::pair<const int, int>, std::pair<const int, int>&, std::pair<const int, int>*>, bool> (*)(const std::pair<const int, int>&)' Can you tell me why? Thanks. 在2009-07-02，"Steven Watanabe" <watanabesj@gmail.com> 写道：
AMDG
fmingu wrote:
Sorry for my unclearness. But how can I write the line: bind(&std::pow,constant(-1.0),bind(&IIPrimemap::size,var(primemapvec))); correctly and thus the program can be complied. If not so the program can not be complied by Dev-C++ and I am confused about that. I really want to know how to write the line correctly. Please give me an example.
As I have said, you need to cast &std::pow to a specific type of function pointer to resolve the ambiguity. I'll break this down further. a) You need to cast. I assume that you know how casts in C++ work. If not, look up static_cast in your favorite elementary C++ text. b) You need to know the function pointer type to cast to. Do you know what a function pointer type looks like? It's similar to a function declaration. <return type> (*)(<argument types>) for example, given the declaration int foo(char); the type of &foo is int(*)(char). Since there are several overloads of std::pow, you need to pick the one that is most appropriate.
In Christ, Steven Watanabe