Update .rustfmt.toml

.rustfmt.toml

@@ -1 +1,32 @@
-edition = "2021"
+# Rustfmt configuration
+# https://github.com/rust-lang/rustfmt/blob/HEAD/Configurations.md
+
+# Rustfmt cannot format long lines inside macros, but this option detects this.
+# This is unstable (tracking issue: https://github.com/rust-lang/rustfmt/issues/3391)
+error_on_line_overflow = true
+
+# Override the default formatting style.
+# See https://internals.rust-lang.org/t/running-rustfmt-on-rust-lang-rust-and-other-rust-lang-repositories/8732/81.
+use_small_heuristics = "Max"
+# See https://github.com/rust-dev-tools/fmt-rfcs/issues/149.
+# This is unstable (tracking issue: https://github.com/rust-lang/rustfmt/issues/3370)
+overflow_delimited_expr = true
+# This is unstable (tracking issue: none).
+imports_granularity = "Crate"
+# This is unstable (tracking issue: none).
+group_imports = "StdExternalCrate"
+
+# Apply rustfmt to more places.
+# This is unstable (tracking issue: https://github.com/rust-lang/rustfmt/issues/3348).
+format_code_in_doc_comments = true
+
+# Automatically fix deprecated style.
+use_field_init_shorthand = true
+use_try_shorthand = true
+
+# Set the default settings again to always apply the proper formatting without
+# being affected by the editor settings.
+edition = "2018"
+hard_tabs = false
+newline_style = "Unix"
+tab_spaces = 4