From f096c615c36cd9217fbd1f8642e4a33fb6701558 Mon Sep 17 00:00:00 2001
From: Vladislav Nepogodin <nepogodin.vlad@gmail.com>
Date: Sun, 19 Dec 2021 21:37:21 +0400
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A5=20conditional=5Fcast?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 include/spdlog/common.h         | 18 ++++++++++++++++--
 include/spdlog/details/os-inl.h |  4 ++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/include/spdlog/common.h b/include/spdlog/common.h
index 9903463c..620b4757 100644
--- a/include/spdlog/common.h
+++ b/include/spdlog/common.h
@@ -30,7 +30,7 @@
 #                define SPDLOG_API __declspec(dllimport)
 #            endif
 #        else // !defined(_WIN32)
-#            define SPDLOG_API __attribute__((visibility ("default")))
+#            define SPDLOG_API __attribute__((visibility("default")))
 #        endif
 #    else // !defined(SPDLOG_SHARED_LIB)
 #        define SPDLOG_API
@@ -320,13 +320,27 @@ struct file_event_handlers
 };
 
 namespace details {
+
+// to avoid useless casts (see https://github.com/nlohmann/json/issues/2893#issuecomment-889152324)
+template<typename T, typename U, std::enable_if_t<!std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value)
+{
+    return static_cast<T>(value);
+}
+
+template<typename T, typename U, std::enable_if_t<std::is_same<T, U>::value, int> = 0>
+constexpr T conditional_static_cast(U value)
+{
+    return value;
+}
+
 // make_unique support for pre c++14
 
 #if __cplusplus >= 201402L // C++14 and beyond
 using std::make_unique;
 #else
 template<typename T, typename... Args>
-std::unique_ptr<T> make_unique(Args &&... args)
+std::unique_ptr<T> make_unique(Args &&...args)
 {
     static_assert(!std::is_array<T>::value, "arrays not supported");
     return std::unique_ptr<T>(new T(std::forward<Args>(args)...));
diff --git a/include/spdlog/details/os-inl.h b/include/spdlog/details/os-inl.h
index 16f3d2e9..e094e0f7 100644
--- a/include/spdlog/details/os-inl.h
+++ b/include/spdlog/details/os-inl.h
@@ -405,9 +405,9 @@ SPDLOG_INLINE int pid() SPDLOG_NOEXCEPT
 {
 
 #ifdef _WIN32
-    return static_cast<int>(::GetCurrentProcessId());
+    return conditional_static_cast<int>(::GetCurrentProcessId());
 #else
-    return static_cast<int>(::getpid());
+    return conditional_static_cast<int>(::getpid());
 #endif
 }