commit 8809982e0d0c3710c09191d40bba5ba58abbc18e
author William A. Kennington III <wak@google.com> Thu Aug 16 18:06:02 2018 -0700
committer William A. Kennington III <wak@google.com> Thu Aug 16 18:13:13 2018 -0700
tree 846f60e31b47514a7ed12b1033a0f27e4f695422
parent 6b3d1051029e0f725103a88e0c58f8a20e539b67

internal/fd: Make it possible to not own the original fd

src/gpioplus/event.cpp

diff --git a/src/gpioplus/event.cpp b/src/gpioplus/event.cpp
index 3fc4062..d7e3716 100644
--- a/src/gpioplus/event.cpp
+++ b/src/gpioplus/event.cpp
@@ -4,6 +4,7 @@
 #include <optional>
 #include <stdexcept>
 #include <system_error>
+#include <type_traits>
 
 namespace gpioplus
 {
@@ -46,7 +47,7 @@
 Event::Event(const Chip& chip, uint32_t line_offset, HandleFlags handle_flags,
              EventFlags event_flags, const char* consumer_label) :
     fd(build(chip, line_offset, handle_flags, event_flags, consumer_label),
-       chip.getFd().getSys())
+       std::false_type(), chip.getFd().getSys())
 {
 }
 

src/gpioplus/handle.cpp

diff --git a/src/gpioplus/handle.cpp b/src/gpioplus/handle.cpp
index 30dc12f..30b43d8 100644
--- a/src/gpioplus/handle.cpp
+++ b/src/gpioplus/handle.cpp
@@ -3,6 +3,7 @@
 #include <linux/gpio.h>
 #include <stdexcept>
 #include <system_error>
+#include <type_traits>
 
 namespace gpioplus
 {
@@ -74,7 +75,8 @@
 
 Handle::Handle(const Chip& chip, const std::vector<Line>& lines,
                HandleFlags flags, const char* consumer_label) :
-    fd(build(chip, lines, flags, consumer_label), chip.getFd().getSys()),
+    fd(build(chip, lines, flags, consumer_label), std::false_type(),
+       chip.getFd().getSys()),
     nlines(lines.size())
 {
 }

src/gpioplus/internal/fd.cpp

diff --git a/src/gpioplus/internal/fd.cpp b/src/gpioplus/internal/fd.cpp
index ef7c719..12a2f40 100644
--- a/src/gpioplus/internal/fd.cpp
+++ b/src/gpioplus/internal/fd.cpp
@@ -19,7 +19,21 @@
     }
 }
 
-Fd::Fd(int fd, const Sys* sys) : sys(sys), fd(fd)
+static int dup(int oldfd, const Sys* sys)
+{
+    int fd = sys->dup(oldfd);
+    if (fd < 0)
+    {
+        throw std::system_error(errno, std::generic_category(), "Duping FD");
+    }
+    return fd;
+}
+
+Fd::Fd(int fd, const Sys* sys) : sys(sys), fd(dup(fd, sys))
+{
+}
+
+Fd::Fd(int fd, std::false_type, const Sys* sys) : sys(sys), fd(fd)
 {
 }
 
@@ -35,16 +49,6 @@
     }
 }
 
-static int dup(int oldfd, const Sys* sys)
-{
-    int fd = sys->dup(oldfd);
-    if (fd < 0)
-    {
-        throw std::system_error(errno, std::generic_category(), "Duping FD");
-    }
-    return fd;
-}
-
 Fd::Fd(const Fd& other) : sys(other.sys), fd(dup(other.fd, sys))
 {
 }

src/gpioplus/internal/fd.hpp

diff --git a/src/gpioplus/internal/fd.hpp b/src/gpioplus/internal/fd.hpp
index 7f54b81..4fb19cd 100644
--- a/src/gpioplus/internal/fd.hpp
+++ b/src/gpioplus/internal/fd.hpp
@@ -1,5 +1,6 @@
 #pragma once
 #include <gpioplus/internal/sys.hpp>
+#include <type_traits>
 
 namespace gpioplus
 {
@@ -11,6 +12,7 @@
   public:
     Fd(const char* pathname, int flags, const Sys* sys);
     Fd(int fd, const Sys* sys);
+    Fd(int fd, std::false_type, const Sys* sys);
     ~Fd();
 
     Fd(const Fd& other);