[MesonToolchain] Adding default dirs

[franramirez688]

Changelog: Feature: Adding default directories to MesonToolchain.
Docs: conan-io/docs#2652

Closes: #9713
Closes: #11596

Note: Using the basic_layout seems to be enough for now.

[franramirez688]

Missing these lines from new Meson build-helper

[SSE4]

it would be helpful to add some test/example on how to use basic_layout together with MesonToolchain. AFAIK existing meson tests don't create an instance of basic_layout...

[franramirez688]

AFAIK existing meson tests don't create an instance of basic_layout...

The meson_lib template is using that layout and we already have this functional test test_meson_lib_template using it. Should it be enough? Perhaps I could add another one if you think that is really needed.

[SSE4]

The meson_lib template is using that layout and we already have this functional test test_meson_lib_template using it. Should it be enough? Perhaps I could add another one if you want is really needed.

yeah, as I have figured it out from https://docs.conan.io/en/latest/reference/conanfile/tools/layout.html?highlight=basic_layout#basic-layout:

from conan.tools.layout import basic_layout

def layout(self):
    basic_layout(self)

and conanfile_sources_v2 does exactly that.

[memsharded]

Looking good!

[memsharded]

I think if so much replace of the initial template is going to happen, then maybe it is worth to define things here?

I am also happy if we add the install bit to the meson templates, for example, adding a License, and making sure that the install is packaging the license too?