added optional logging

Cargo.toml

@@ -13,3 +13,4 @@ openssl = "0.10.33"
 stackalloc = "1.1.0"
 pin-project = "1.0.6"
 bytes = "0.5.6"
+log = {version = "0.4.14", optional=true}

src/ext.rs

@@ -202,6 +202,66 @@ where F: FnOnce(&mut [u8]) -> T
 }
 
 
+#[macro_export] macro_rules! lazy_format {
+    ($msg:literal $($tt:tt)*) => {
+	{
+	    use ::std::fmt::{self, Write, Formatter};
+	    use ::std::sync::Mutex;
+	    use ::std::io;
+	    
+	    let pfn = move |fmt| {
+		write!(fmt, $msg $($tt)*)?;
+		let mut sfmt = String::new();
+		write!(&mut sfmt, $msg $($tt)*)?;
+		Ok(sfmt)
+	    };
+
+	    enum LazyFormatInner<F>
+	    {
+		//todo: redo this entire thing
+
+		Pending(F),
+		Complete(String),
+		Error(fmt::Error),
+		Panicked,
+	    }
+
+	    struct LazyFormat<F>(Mutex<LazyFormatInner<F>>);
+	    
+	    impl<F: FnOnce(&mut fmt::Formatter<'_>) -> io::Result<String>> fmt::Display for LazyFormat<F>
+	    {
+		fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
+		{
+		    //todo: redo this entire thing
+		    /*
+		    let mut inner = self.0.lock().unwrap();
+		    let this = std::mem::replace(inner, LazyFormatInner::Panicked);
+		    //TODO: impl fmt::Write wrapper that multi-writes to 2 outputs
+		    let string = match this {
+		    LazyFormatInner::Pending(func) => func(f),
+		    LazyFormatInner::Complete(string) => write!(f, "{}", string).map(move |_| string),
+		    LazyFormatInner::Error(err) => return Err(err),
+		    LazyFormatInner::Panicked => panic!(),
+		};
+		    match string {
+		    Err(err) => {
+		     *inner = LazyFormatInner::Error(err),
+		},
+		}*/
+		}
+	    }
+	}
+    }
+}
+
+#[cfg(not(feature="log"))] #[macro_export] macro_rules! trace {
+    ($fmt:literal $($tt:tt)*) => {
+	{
+	    ((), $($tt)*);
+	}
+    }
+}
+
 pub mod bytes
 {
     use super::*;
@@ -216,3 +276,4 @@ pub mod bytes
 
 mod slice;
 pub use slice::*;
+

src/lib.rs

@@ -2,6 +2,7 @@
 #![allow(dead_code)]
 
 #[macro_use] extern crate pin_project;
+#[cfg(feature="log")] #[macro_use] extern crate log;
 
 // Extensions & macros
 #[macro_use] mod ext;