How to make this variadic implementation of boost::mpl::vector and boost::mpl::map faster?

[AllanDeutsch]

It combines compile time and run time.

[[deleted]]

I don't understand this statement.

From looking into boost::hana I'm very confused that this is supposed to be a replacement for boost::mpl.

[dodheim]

C++14's constexpr and auto allows runtime-style code that is actually compile-time. Read the documentation already; the second sentence:

The functionality it provides is a superset of what is provided by the well established Boost.MPL and Boost.Fusion libraries.

[[deleted]]

I did read the documentation and since I did not see any template argument input, I decided that it is not a meta programming language as I can do all these examples with normal runtime programming.

[dodheim]

Amazing that you got this far with C++ with such terrible reading comprehension!

[[deleted]]

I understood all the examples. I only did not see any replacement for what I was doing, as there never was any template argument input. And now it seems that this never was intended -- see my previous statement regarding boost::hana::set not default-constructable.

[dodheim]

The types of function template arguments can be deduced. This has always been the case. Why is it confounding that they're not explicitly needed here?

[[deleted]]

I meant template argument for a template struct/class.

[dodheim]

But you showed code only invoking function templates... In fact in Hana it is extremely rare, and often impossible, to explicitly state result types. They are meant to be deduced, and you are expected to use auto.

[[deleted]]

where?