Extension of Nd range

[tobiasweinzierl80]

Description

We found that it is very useful for our code if we can construct the range from plain integers. For this, the underlying datatype storing the ranges has to be changed to vector. This should have no negative impact on the performance. However, it makes using the class easier.

The class could do with more assertions and more docu.

Type of change

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• [ ] bug fix - change that fixes an issue
• [X ] new feature - change that adds functionality
• [ ] tests - change in tests
• [ ] infrastructure - change in infrastructure and CI
• [ X] documentation - documentation update

Tests

• [ ] added - required for new features and some bug fixes
• [ X] not needed

Documentation

• [ X] updated in #555 of spec
• [ ] needs to be updated
• [ ] not needed

Breaks backward compatibility

• [ ] Yes
• [ X] No
• [ ] Unknown

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Other information

[sasalla23]

I have implemented the changes discussed in the spec as well as the changes concerning std::array. The initialization of the array in the constructor with parameter size[N] as described by @akukanov works from what I tested. As I said in the spec, I have removed the constructor that uses begin[N] and end[N] and renamed ndims to dim_count. Let me know if this poses a problem or if there is anything missing.