Doc aliases for C & renamed functions

Improve final type heuristic to also check for unknown instance structs

Generate `impl` blocks for associated enum functions

Use `cargo:warning` instead of `eprintln!` for printing warnings

The latter just disappears instead of being printed.

Fixes https://github.com/gtk-rs/gir/issues...

Complements: 5ce31f2 ("codegen: Add version condition on special function traits")

When get_name or to_string is available and adheres to the right
conditions a Display impl lever...

Analysis was copied from enums which adds an std::fmt when
generate_display_trait is true, but t...

This not only cleans up unnecessary mutable variables in the codegen
loop and a cloned Imports i...

This function is responsible for generating a Display impl, and caused
unused std::fmt import pr...

This is used in enum function generation where all enum types
asssociated with a given crate are...

`crate::ffi`, which these calls resolve to are ignored in
Imports::common_checks, no need to pas...

This function always returns the value from sys_crate_name.

These always show up in the .gir file but for final types there wouldn't
be any fields inside it...

don't be verbose on missing c:type on internal fields

cargo_toml: Do not overwrite library name for unversioned system-deps

See: https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/565#note_709394

In ...

Revert "Switch to doc cfg instead of feature dox"

codegen: Explicitly use glib::Value instead of importing

Fixes an issue where glib::Value could conflict with other
things named "Value"

Use write_str instead of write_fmt when no formatting is needed

codegen: Add version condition on special function traits

Write_fmt (what write! expands to) needs to be set up with an
std::fmt::Arguments object that is...

Switch to doc cfg instead of feature dox

Add 2018 edition to tests

config/members: add manual to wanted check

Now that paths can be specified on the commandline the depth level does
not need to represent sy...

Argparse conveniently prints the name of the argument that failed
parsing.

gir-directory mentally conflicts with the directory for `gir`, rather
than the specifically-name...

Switch 2018

fixes #1000

This is not needed any longer

See https://github.com/gtk-rs/gtk-rs/pull/156

codegen/enum: Do not generate doc(cfg) on match arms

Solves warnings of the following kind in gtk-rs:

warning: unused doc comment
--> gtk...

warning: unused doc comment
--> gstreamer/src/auto/enums.rs:761:41
|
761 | ...

Simplify `match` blocks into `?` operator using SSR

Using Rust-analyzer SSR:

match $a {Ok($b) => $c, Err($e) => return Err($d)} ==>> $a.map_err...

Using Rust-analyzer SSR:

match $a {Some($b) => $c, None => return Err($d)} ==>> $a.ok_or($d...

Using Rust-analyzer SSR with:

match $a {Some($b) => $c, None => return None} ==>> $a?