From 993710eb169f555dc1b942e2f32c2805381e1df8 Mon Sep 17 00:00:00 2001
From: Adam Crume <acrume@google.com>
Date: Thu, 31 May 2018 19:57:23 -0700
Subject: [PATCH] Use compile_error! instead of panicking

Fixes #1168
---
 serde_derive/src/lib.rs | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/serde_derive/src/lib.rs b/serde_derive/src/lib.rs
index 708f3bf4..33b0aee9 100644
--- a/serde_derive/src/lib.rs
+++ b/serde_derive/src/lib.rs
@@ -53,6 +53,7 @@ extern crate proc_macro2;
 
 mod internals;
 
+use std::str::FromStr;
 use proc_macro::TokenStream;
 use syn::DeriveInput;
 
@@ -71,7 +72,7 @@ pub fn derive_serialize(input: TokenStream) -> TokenStream {
     let input: DeriveInput = syn::parse(input).unwrap();
     match ser::expand_derive_serialize(&input) {
         Ok(expanded) => expanded.into(),
-        Err(msg) => panic!(msg),
+        Err(msg) => TokenStream::from_str(&format!("compile_error!({:?});", msg)).unwrap(),
     }
 }
 
@@ -80,6 +81,6 @@ pub fn derive_deserialize(input: TokenStream) -> TokenStream {
     let input: DeriveInput = syn::parse(input).unwrap();
     match de::expand_derive_deserialize(&input) {
         Ok(expanded) => expanded.into(),
-        Err(msg) => panic!(msg),
+        Err(msg) => TokenStream::from_str(&format!("compile_error!({:?});", msg)).unwrap(),
     }
 }