My take on this. 20.8.10.1.2/10 in N3225 The values of the bound arguments v1, v2, …, vN and their corresponding types V1, V2, …, VN depend on the types TiD derived from the call to bind and the cv-qualifiers cv of the call wrapper g as follows: if TiD is reference_wrapper, the argument is tid.get() … Read more
boost::bind has overloaded relational operators, std::bind does not. boost::bind supports non-default calling conventions, std::bind is not guaranteed to (standard library implementations may offer this as an extension). boost::bind provides a direct mechanism to allow one to prevent eager evaluation of nested bind expressions (boost::protect), std::bind does not. (That said, one can use boost::protect with std::bind … Read more
std::bind is for partial function application. That is, suppose you have a function object f which takes 3 arguments: f(a,b,c); You want a new function object which only takes two arguments, defined as: g(a,b) := f(a, 4, b); g is a “partial application” of the function f: the middle argument has already been specified, and … Read more
Ignoring extra arguments is a lot simpler to implement, and can actually be useful. In a typical implementation e.g. libstdc++ (g++), the approach taken is to collect the operator() arguments into a tuple and then let the std::placeholder bind arguments extract them as required. Enforcing argument count would require counting the number of used placeholders, … Read more
When you say “the first argument is a reference” you surely meant to say “the first argument is a pointer“: the & operator takes the address of an object, yielding a pointer. Before answering this question, let’s briefly step back and look at your first use of std::bind() when you use std::bind(my_divide, 2, 2) you … Read more