Dirk Stolle

Changes have been rebased against the current `develop` branch. Furthermore, `std::size_t` is replaced by `boost::gil::index_t` in the affected files. At the moment `boost::gil::index_t` is an alias for `std::ptrdiff_t`, as suggested...

@mloskot: > Do you want me to squeeze it for Boost 1.80? Today is a deadline for major changes. __No.__ The deadline passed yesterday, so I guess it's not really...

> The two issues which I see are: > > * It has merge conflicts that need to be resolved. > I did not have the time to resolve them...

> A rationale could be that int is used almost [everywhere](https://github.com/boostorg/gil/blob/develop/include/boost/gil/color_base_algorithm.hpp) to identify the channel. Everywhere - except where it is not used. While `nth_channel_view` still uses `int` (unless #659...

I was not really expecting that people do arithmetic operations on the number of channels, but if that is a concern, then some signed type may indeed be better. In...

> We're still having some support from Azure Pipelines, however it's different (or not) from the GA, who knows. Azure Pipelines is in the process of removing Windows Server 2016...

> * We need to disable certain compilers Yeah. I'd like to remove Clang 3.5, 3.6, 3.7 and 3.8 from the GitHub Actions (=GHA) workflows and would have done so...

@jonschlinkert I was just about to create a similar pull request before I saw this one. So is there any chance to get this change merged?

> On a unix target the previous code runs in only 9112ms > However on a WebAssembly target it runs in 33453ms. > > Both are built for release. >...

> One question I have here: today, once_cell's MSRV is described as "conservative" in readme and 11 months for _me_ does sound conservative, though pretty close to the boundary. I'd...