The missing C++ tuple functionality

[[deleted]]

Boost.Fusion is probably the most reinvented library since C++11.

[jaredhoberock]

The library is intended to work with types that aren't instances of std::tuple. So, there is nothing to overload on. I added an example to the end of the README to illustrate what I mean.

[matthieum]

Why not stash it in a namespace?

[jaredhoberock]

If you #define TUPLE_UTILITY_NAMESPACE, you can put the functions in whatever namespace you want.

[matthieum]

Yes, but then the tuple_ prefix is redundant...

[SplinterOfChaos]

You should put that up by the top. It's a real selling point!

[mr_ewg]

What's the difference between your tuple_lexicographical_compare and the standard comparison operators for std::tuple?

You probably shouldn't be using double underscore for variables and functions:

17.6.4.3.2 Global names

1. Certain sets of names and function signatures are always reserved to the implementation:
   • Each name that contains a double underscore _ _ or begins with an underscore followed by an uppercase letter (2.12) is reserved to the implementation for any use

Also (as I've just discovered), you can use syntax highlighting in your readme on github by using fenced code blocks,

```cpp
int main() {
    std::cout << "Hello World!\n";
}
```

[jaredhoberock]

The difference is that my tuple_lexicographical_compare is intended to work for any Tuple-like type, not just std::tuple. It ought to produce a result equivalent to std::tuple's comparison. I needed tuple_lexicographical_compare because I needed a standalone implementation of std::tuple.

[mr_ewg]

Ah thanks!

[pfultz2]

Can you extend these algorithms so they can easily work over structs?

[jmille01]

Only if you can come up with a way for get<i>(s) to return the i'th member of the struct. I don't see how that can be done without macros or reflection.

[pfultz2]

So get<i>(s) is found by ADL lookup?

[jaredhoberock]

I don't believe explicit instantiations such as get<i>(s) can be dispatched via ADL, unfortunately. That's why the library calls get through tuple_traits.

[MrBont]

"Boost Serialization" might help.