Problems migrating from STL to ETL about etl

[nlohmann]

Hi there! Any reaction on this?

[jwellbelove]

Sorry to be so late in replying, but I've been on holiday in India for the last two weeks and I had very limited internet access!

It looks like the GCC version you are using doesn't support static_assert. At the moment the header assumes that GCC supports this. I will have to add some macro definitions to check the GCC version, but in the mean time you could comment out the following lines in static_assert.h

#elif defined(ETL_COMPILER_GCC)
#define STATIC_ASSERT(Condition, Message) static_assert(Condition, Message)

I have a few other fixes and improvements to upload, but a glitch with Git just before I went away meant I will have to rebuild a few of them. :-(

[nlohmann]

I am using g++-5 (Homebrew gcc5 5.4.0) 5.4.0 - this version supports static_assert.

[jwellbelove]

OK, I think I get what the problem is, but I'm not sure of the solution as yet.

[jwellbelove]

Does your configuration have -std=c++11 set?

[nlohmann]

Yes. Von meinem iPhone gesendet

…

Am 12.12.2016 um 10:25 schrieb John Wellbelove ***@***.***>: Does your configuration have -std=c++11 set? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub, or mute the thread.

[jwellbelove]

The problem seems to be that GCC doesn't like this code...

template <std::size_t I, typename T, std::size_t MAXN>
inline T& get(array<T, MAXN>& a)
{
static_assert(I < MAXN, "Index out of bounds"); <<<<<<<<<<<<<<<<<<<
return a[I];
}

error: there are no arguments to 'static_assert' that depend on a template parameter, so a declaration of 'static_assert' must be available [-fpermissive]

The call to static assert already depends on template non-type parameters I & MAXN.
I'm assuming that it must depend on either 'a' or maybe the type T too?
I need to experiment.
You could either comment out the STATIC_ASSERT macro as previously mentioned of temporarily comment out the STATIC_ASSERTs in etl::array until I have a solution.

[jwellbelove]

I can only get this to fail if I select "-std=c++98"
If I select "-std=c++11" then I get no warnings.

[nlohmann]

I tried again with the most recent release. The error does not occur any more. I am puzzled. Sorry for troubling you.

I now try to get the JSON library to compile with ETL.