feat: slog - add ability to store nested values

struct Item {...}

let inner = Item {...}
info!(root, "Info breadcrumb"; "nested" => Item);

Author: shenek

Cargo.toml

@@ -30,6 +30,7 @@ with_log = ["log", "with_backtrace"]
 with_debug_to_log = ["log"]
 with_env_logger = ["with_log", "env_logger"]
 with_slog = ["slog", "serde_json"]
+with_slog_nested = ["with_slog", "slog/nested-values"]
 with_error_chain = ["error-chain", "with_backtrace"]
 with_device_info = ["libc", "hostname", "uname", "with_client_implementation"]
 with_rust_info = ["rustc_version", "with_client_implementation"]

src/integrations/slog.rs

@@ -119,6 +119,12 @@ impl Serializer for StoringSerializer {
     // impl_number!(u128 => emit_u128);
     // impl_number!(i128 => emit_i128);
 
+    #[allow(missing_docs)]
+    #[cfg(feature = "with_slog_nested")]
+    fn emit_serde(&mut self, key: slog::Key, value: &dyn slog::SerdeValue) -> slog::Result {
+        self.emit_serde_json_value(key, serde_json::json!(value.as_serde()))
+    }
+
     #[allow(missing_docs)]
     fn emit_arguments(&mut self, _: slog::Key, _: &fmt::Arguments) -> slog::Result {
         Ok(())

src/lib.rs

@@ -109,6 +109,7 @@
 //!   is currently the default transport.
 //! * `with_curl_transport`: enables the curl transport.
 //! * `with_slog`: enables the `slog` integration
+//! * `with_slog_nested`: enables the `slog` integration with ability to store nested structures
 #![warn(missing_docs)]
 
 #[macro_use]