docs: Clarify relationship with log / tracing

.clippy.toml

@@ -1 +1 @@
-msrv = "1.54.0"  # MSRV
+msrv = "1.56.0"  # MSRV

.github/workflows/ci.yml

@@ -51,15 +51,15 @@ jobs:
     - name: No-default features
       run: cargo test --workspace --no-default-features
   msrv:
-    name: "Check MSRV: 1.54.0"
+    name: "Check MSRV: 1.56.0"
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
       uses: actions/checkout@v2
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.54.0  # MSRV
+        toolchain: 1.56.0  # MSRV
         profile: minimal
         override: true
     - uses: Swatinem/rust-cache@v1
@@ -113,7 +113,7 @@ jobs:
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.54.0  # MSRV
+        toolchain: 1.56.0  # MSRV
         profile: minimal
         override: true
         components: clippy

.github/workflows/rust-next.yml

@@ -57,9 +57,9 @@ jobs:
     strategy:
       matrix:
         rust:
-        - 1.54.0  # MSRV
+        - 1.56.0  # MSRV
         - stable
-    continue-on-error: ${{ matrix.rust != '1.54.0' }}  # MSRV
+    continue-on-error: ${{ matrix.rust != '1.56.0' }}  # MSRV
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository

Cargo.toml

@@ -6,7 +6,8 @@ authors = ["Pascal Hertleif <killercup@gmail.com>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-clique/clap-verbosity-flag"
 readme = "README.md"
-edition = "2018"
+edition = "2021"
+rust-version = "1.56.0"  # MSRV
 include = [
   "src/**/*",
   "Cargo.toml",
@@ -33,3 +34,6 @@ clap = { version = "3.0", default-features = false, features = ["std", "derive"]
 
 [dev-dependencies]
 env_logger = "0.9.0"
+tracing = "0.1"
+tracing-subscriber = "0.2"
+tracing-log = "0.1.3"

README.md

@@ -1,4 +1,4 @@
-# clap-verbosity-flag
+# clap-verbosity-flag for `log`
 
 [![Documentation](https://img.shields.io/badge/docs-master-blue.svg)][Documentation]
 ![License](https://img.shields.io/crates/l/clap-verbosity-flag.svg)

examples/example.rs

@@ -14,4 +14,10 @@ fn main() {
     env_logger::Builder::new()
         .filter_level(cli.verbose.log_level_filter())
         .init();
+
+    log::error!("Engines exploded");
+    log::warn!("Engines smoking");
+    log::info!("Engines exist");
+    log::debug!("Engine temperature is 200 degrees");
+    log::trace!("Engine subsection is 300 degrees");
 }

examples/example_tracing.rs

@@ -0,0 +1,34 @@
+use clap::Parser;
+use clap_verbosity_flag::Verbosity;
+
+/// Foo
+#[derive(Debug, Parser)]
+struct Cli {
+    #[clap(flatten)]
+    verbose: Verbosity,
+}
+
+fn main() {
+    let cli = Cli::parse();
+
+    tracing_subscriber::fmt()
+        .with_max_level(convert_filter(cli.verbose.log_level_filter()))
+        .init();
+
+    log::error!("Engines exploded");
+    log::warn!("Engines smoking");
+    log::info!("Engines exist");
+    log::debug!("Engine temperature is 200 degrees");
+    log::trace!("Engine subsection is 300 degrees");
+}
+
+fn convert_filter(filter: log::LevelFilter) -> tracing_subscriber::filter::LevelFilter {
+    match filter {
+        log::LevelFilter::Off => tracing_subscriber::filter::LevelFilter::OFF,
+        log::LevelFilter::Error => tracing_subscriber::filter::LevelFilter::ERROR,
+        log::LevelFilter::Warn => tracing_subscriber::filter::LevelFilter::WARN,
+        log::LevelFilter::Info => tracing_subscriber::filter::LevelFilter::INFO,
+        log::LevelFilter::Debug => tracing_subscriber::filter::LevelFilter::DEBUG,
+        log::LevelFilter::Trace => tracing_subscriber::filter::LevelFilter::TRACE,
+    }
+}

src/lib.rs

@@ -1,4 +1,4 @@
-//! Easily add a `--verbose` flag to CLIs using Structopt
+//! Control `log` level with a `--verbose` flag for your CLI
 //!
 //! # Examples
 //!