Add example for nothreads mode

Author: rasky

Cargo.toml

@@ -10,6 +10,7 @@ documentation = "https://docs.rs/slog"
 homepage = "https://github.com/slog-rs/slog"
 repository = "https://github.com/slog-rs/slog"
 readme = "README.md"
+autoexamples = true
 
 build = "build.rs"
 
@@ -49,6 +50,10 @@ release_max_level_trace = []
 [dependencies]
 erased-serde = { version = "0.3", optional = true }
 
+[[example]]
+name = "singlethread"
+required-features = ["nothreads"]
+
 [package.metadata.docs.rs]
 features = ["std", "nested-values", "dynamic-keys"]
 

Makefile

@@ -48,8 +48,10 @@ longtest:
 	@i=0; while i=$$((i + 1)) && echo "Iteration $$i" && make test ; do :; done
 
 .PHONY: $(EXAMPLES)
-$(EXAMPLES):
+named struct-log-self:
 	cargo build --example $@ $(CARGO_FLAGS)
+singlethread:
+	cargo build --features nothreads --example $@ $(CARGO_FLAGS)
 
 .PHONY: doc
 doc: FORCE

examples/singlethread.rs

@@ -0,0 +1,29 @@
+//#![feature(nothreads)]
+#[macro_use]
+extern crate slog;
+use slog::{Fuse, Logger};
+use std::cell::RefCell;
+use std::rc::Rc;
+
+mod common;
+
+#[derive(Clone)]
+struct NoThreadSafeObject {
+    val: Rc<RefCell<usize>>,
+}
+
+fn main() {
+    let log = Logger::root(Fuse(common::PrintlnDrain), o!("version" => "2"));
+    let obj = NoThreadSafeObject {
+        val: Rc::new(RefCell::new(4)),
+    };
+
+    // Move obj2 into a closure. Since it's !Send, this only works
+    // with nothreads feature.
+    let obj2 = obj.clone();
+    let sublog = log.new(o!("obj.val" => slog::FnValue(move |_| {
+        format!("{}", obj2.val.borrow())
+    })));
+
+    info!(sublog, "test");
+}