Simplified the move semantics by avoiding virtual functions

Author: mikucionisaau

source/matplot/util/popen.cpp

@@ -169,9 +169,9 @@ int common_pipe::close(int *exit_code)
 {
     if (!opened())
         return 0;
-    fclose(file_);
+    ::fclose(file_);
     file_ = nullptr;
-    while (waitpid(pid, exit_code, 0) == -1) {
+    while (::waitpid(pid, exit_code, 0) == -1) {
         if (errno != EINTR) {
             if (exit_code != nullptr)
                 *exit_code = -1;
@@ -190,6 +190,10 @@ inline int common_pipe::error(int code, const std::string& what) const
     return code;
 }
 
+ipipe::ipipe() = default; // starting with C++20 could be in-class
+
+opipe::opipe() = default; // starting with C++20 could be in-class
+
 int opipe::write(std::string_view data)
 {
     constexpr auto CSIZE = sizeof(std::string_view::value_type);

source/matplot/util/popen.h

@@ -16,10 +16,8 @@
 /// State of a child process pipe
 class proc_pipe 
 {
-public:
-    proc_pipe() = default;
-
 protected:
+    proc_pipe() = default;
     HANDLE hProcess = 0; ///< WIN32 process handle
     HANDLE hThread = 0; ///< WIN32 thread handle
     FILE *file_ = nullptr; ///< C file handle for I/O (not both)
@@ -32,10 +30,8 @@ class proc_pipe
 /// State of a child process pipe
 class proc_pipe
 {
-public:
-    proc_pipe() = default;
-
 protected:
+    proc_pipe() = default;
     pid_t pid = 0;         ///< POSIX process identifier
     FILE *file_ = nullptr; ///< C file handle for input or output (not both)
 };
@@ -48,18 +44,22 @@ class proc_pipe
 class common_pipe : public proc_pipe 
 {
 public:
-    common_pipe() : proc_pipe{} {}
-    virtual ~common_pipe() noexcept {
-        if (opened())
-            close();
-    }
     FILE *file() const { return file_; }
     int close(int *exit_code = nullptr);
     bool opened() const { return file_ != nullptr; }
     bool exceptions() const { return exceptions_; }
     void exceptions(bool exc) { exceptions_ = exc; }
 
 protected:
+    common_pipe() = default;
+    common_pipe(const common_pipe&) = delete;
+    common_pipe& operator=(const common_pipe&) = delete;
+    common_pipe(common_pipe&&) noexcept = default;
+    common_pipe& operator=(common_pipe&&) noexcept = default;
+    ~common_pipe() noexcept {
+        if (opened())
+            close();
+    }
     bool exceptions_ = false;
     int error(int err, const std::string& what) const;
     int open(const std::string &command, char mode);
@@ -69,7 +69,7 @@ class common_pipe : public proc_pipe
 class ipipe : public common_pipe 
 {
 public:
-    ipipe() : common_pipe{} {}
+    ipipe();
     int open(const std::string &cmd) { return common_pipe::open(cmd, 'r'); }
     int read(std::string &data);
 };
@@ -78,7 +78,7 @@ class ipipe : public common_pipe
 class opipe : public common_pipe 
 {
 public:
-    opipe() : common_pipe{} {}
+    opipe();
     int open(const std::string &cmd) { return common_pipe::open(cmd, 'w'); }
     int write(std::string_view data);
     int flush(std::string_view data = {});