added boolinq::mut_from and modified for each to be able to mutate

[LennardR]

Currently compiles only with MSVC!

Propeses a Solution for #55 by introducing a mut_from function.

To enable the normal from function to be able to create mutable Linq Objects would require extensive reworking of existing code.

[k06a]

@LennardR could you restore updated formatting to keep changes more focused?

[LennardR]

Yeah, don't know how that happend.

[k06a]

Why can't utilize the same LinqEndException exception for this mutable case?

[LennardR]

You can utilize the same exception. You can remove the LinqNonMutableException completely.
But for Debugging and using the Lib I think it is cleaner to have a dedicated Exception.

[k06a]

I see compilation error on GCC and Clang is that you use function template param T while the class has same template name T: https://app.travis-ci.com/github/k06a/boolinq/jobs/558567721#L631-L641

In file included from /home/travis/build/k06a/boolinq/test/AllTest.cpp:6:0:
[632]()/home/travis/build/k06a/boolinq/include/boolinq/boolinq.h:111:18: error: declaration of ‘class T’
[633]()         template<typename T,
[634]()                  ^
[635]()In file included from /home/travis/build/k06a/boolinq/test/AllTest.cpp:6:0:
[636]()/home/travis/build/k06a/boolinq/include/boolinq/boolinq.h:47:26: error:  shadows template parm ‘class T’
[637]()     template<typename S, typename T>
[638]()                          ^
[639]()In file included from /home/travis/build/k06a/boolinq/test/AllTest.cpp:6:0:
[640]()/home/travis/build/k06a/boolinq/include/boolinq/boolinq.h:112:82: error: expected ‘>’ before ‘=’ token
[641]()   typename = std::enable_if < std::is_lvalue_reference<T>::value,bool> = false>

Try to rename the template parameter name to something else.