From 461e7d3d73ca4928d9bd132dafede1e3db35a93b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?=
 <barnabas.pocze@ideasonboard.com>
Date: Thu, 15 Jan 2026 11:51:47 +0100
Subject: [PATCH] libcamera: base: utils: Simplify `operator<<` for `Duration`
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There is no real need for a function template. It is not defined in a
header file, so it has limited availability, and there exists only a
single instantion.

So convert it to use `std::ostream` directly, like most `operator<<`
in the code base.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 include/libcamera/base/utils.h |  4 +---
 src/libcamera/base/utils.cpp   | 11 ++---------
 2 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/include/libcamera/base/utils.h b/include/libcamera/base/utils.h
index 2cb8e0a8..198cf152 100644
--- a/include/libcamera/base/utils.h
+++ b/include/libcamera/base/utils.h
@@ -424,9 +424,7 @@ scope_exit(EF) -> scope_exit<EF>;
 } /* namespace utils */
 
 #ifndef __DOXYGEN__
-template<class CharT, class Traits>
-std::basic_ostream<CharT, Traits> &operator<<(std::basic_ostream<CharT, Traits> &os,
-					      const utils::Duration &d);
+std::ostream &operator<<(std::ostream &os, const utils::Duration &d);
 #endif
 
 } /* namespace libcamera */
diff --git a/src/libcamera/base/utils.cpp b/src/libcamera/base/utils.cpp
index 65d9181c..2c3f2b7e 100644
--- a/src/libcamera/base/utils.cpp
+++ b/src/libcamera/base/utils.cpp
@@ -658,11 +658,9 @@ void ScopeExitActions::release()
 } /* namespace utils */
 
 #ifndef __DOXYGEN__
-template<class CharT, class Traits>
-std::basic_ostream<CharT, Traits> &operator<<(std::basic_ostream<CharT, Traits> &os,
-					      const utils::Duration &d)
+std::ostream &operator<<(std::ostream &os, const utils::Duration &d)
 {
-	std::basic_ostringstream<CharT, Traits> s;
+	std::ostringstream s;
 
 	s.flags(os.flags());
 	s.imbue(os.getloc());
@@ -671,11 +669,6 @@ std::basic_ostream<CharT, Traits> &operator<<(std::basic_ostream<CharT, Traits>
 	s << d.get<std::micro>() << "us";
 	return os << s.str();
 }
-
-template
-std::basic_ostream<char, std::char_traits<char>> &
-operator<< <char, std::char_traits<char>>(std::basic_ostream<char, std::char_traits<char>> &os,
-					  const utils::Duration &d);
 #endif
 
 } /* namespace libcamera */