From a2dfde6a63d23a279b11c3e575b847d292f6e788 Mon Sep 17 00:00:00 2001
From: mutouyun <orz@orzz.org>
Date: Sat, 3 Dec 2022 16:29:39 +0800
Subject: [PATCH] upd: [imp] add nodiscard for fmt

---
 benchmark/benchmark_fmt.cpp | 8 ++++----
 include/libimp/fmt.h        | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/benchmark/benchmark_fmt.cpp b/benchmark/benchmark_fmt.cpp
index 0693203..5203c3f 100644
--- a/benchmark/benchmark_fmt.cpp
+++ b/benchmark/benchmark_fmt.cpp
@@ -11,7 +11,7 @@ namespace {
 
 void imp_fmt_string(benchmark::State &state) {
   for (auto _ : state) {
-    imp::fmt("hello world. hello world. hello world. hello world. hello world.");
+    std::ignore = imp::fmt("hello world. hello world. hello world. hello world. hello world.");
   }
 }
 
@@ -23,7 +23,7 @@ void fmt_format_string(benchmark::State &state) {
 
 void imp_fmt_int(benchmark::State &state) {
   for (auto _ : state) {
-    imp::fmt(654321);
+    std::ignore = imp::fmt(654321);
   }
 }
 
@@ -35,7 +35,7 @@ void fmt_format_int(benchmark::State &state) {
 
 void imp_fmt_float(benchmark::State &state) {
   for (auto _ : state) {
-    imp::fmt(654.321);
+    std::ignore = imp::fmt(654.321);
   }
 }
 
@@ -47,7 +47,7 @@ void fmt_format_float(benchmark::State &state) {
 
 void imp_fmt_chrono(benchmark::State &state) {
   for (auto _ : state) {
-    imp::fmt(std::chrono::system_clock::now());
+    std::ignore = imp::fmt(std::chrono::system_clock::now());
   }
 }
 
diff --git a/include/libimp/fmt.h b/include/libimp/fmt.h
index 89dc7b7..26f37a3 100644
--- a/include/libimp/fmt.h
+++ b/include/libimp/fmt.h
@@ -52,12 +52,12 @@ auto spec(char const (&fstr)[N]) noexcept {
 /// @brief String formatting function.
 
 template <typename A>
-std::string fmt(A &&a) {
+LIBIMP_NODISCARD std::string fmt(A &&a) {
   return fmt_to_string(std::forward<A>(a));
 }
 
 template <typename A1, typename... A>
-std::string fmt(A1 &&a1, A &&...args) {
+LIBIMP_NODISCARD std::string fmt(A1 &&a1, A &&...args) {
   std::string joined(fmt(std::forward<A1>(a1)));
   LIBIMP_UNUSED auto unfold = {
     joined.append(fmt_to_string(std::forward<A>(args)))...