Perfect forwarding for methods

I often see perfect forwarding listed for constructor arguments, but not usually for functions with a return or methods. Here is my solution for an method method of class Cls:

template<typename ...Args>
static auto method(Cls* cls, Args &&  ...args)
  -> typename std::result_of<decltype(&Cls::method)(Cls, Args...)>::type {
    return cls->method(std::forward<Args>(args)...);
}

This is useful if you want to call protected classes from a “helper” friend class, for example, to expose them to tests without having to require GoogleTest/GoogleMock to be available for regular users.

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Setting up SSH forwarding

SSH forwarding can improve your security along with reducing the need to type passwords and have multiple keys linked to your GitHub/GitLab instance. The procedure is:

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ssh 

Lua Environment Modules

This is a guide to setting up Lmod (lua environment modules) on a CentOS system. I’ve used a similar procedure to set them up on a Mac, as well, so this is still a useful guide to the workings of Lmod if you use a different system; mostly paths will change. On a Mac, you’ll want to install Lmod from the science tap in brew. There are several good pages covering environment modules (TCL version), but not many that use the newer Lua syntax. This document aims to fill that roll.

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Python 3 upgrade

About ten years ago, Guido Van Rossum, the Python author and Benevolent Dictator for Life (BDFL), along with the Python community, decided to make several concurrent backward incompatible changes to Python 2.5 and release a new version, Python 3.0.

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C++17

The every-three-year cycle has changed the development of C++; we are now getting consistent releases somewhere in-between the major and minor releases of old. The 2017 release may be called minor by some, with a huge portion of the planned improvements being pushed back another 3-6 years, but there were several substantial changes in useful areas; it is much more impactful than C++14, for example. This almost feels like a lead-in release to C++20.

The std::variant, std::optional, and std::any additions to the standard library are huge, and can restructure the way you program (and are available for older C++ releases through Boost and other libraries).

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C++14

Unlike C++11, this is a minor release, focused mostly on improvements on top of C++11 changes, with very little that one could call “new”. C++14 feels a little more natural than C++11 by expanding the usage of features and implementing common sense additions that were missed in the original C++11 release. There were also quite a few bug fixes; several of these were backported into C++11 mode in compilers.

Also, while C++11 is always available in ROOT 6, C++14 requires a flag and compatible compiler, so C++14 features are often unavailable. The Conda-Forge ROOT package has C++17 enabled.

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