use initializer list instead of explicit constructor

src/info.cpp

@@ -1011,7 +1011,7 @@ std::vector<std::string> Info::get_available_styles(const std::string &category)
   } else if (category == "command") {
     return get_style_names(input->command_map);
   }
-  return std::vector<std::string>();
+  return {};
 }
 
 template<typename ValueType>

src/molecule.cpp

@@ -2035,7 +2035,7 @@ std::string Molecule::parse_keyword(int flag, char *line)
 
     MPI_Bcast(&eof,1,MPI_INT,0,world);
     if (eof) {
-      return std::string("");
+      return {""};
     }
 
     // bcast keyword line to all procs

src/platform.cpp

@@ -415,7 +415,7 @@ std::string platform::mpi_info(int &major, int &minor)
   major = 1;
   minor = 0;
 #endif
-  return std::string(version);
+  return {version};
 }
 
 /* ----------------------------------------------------------------------
@@ -543,8 +543,8 @@ void *platform::dlopen(const std::string &fname)
 std::string platform::dlerror()
 {
   const char *errmesg = ::dlerror();
-  if (errmesg) return std::string(errmesg);
-  else return "";
+  if (errmesg) return {errmesg};
+  else return {""};
 }
 
 // close a shared object

src/utils.cpp

@@ -143,7 +143,7 @@ void utils::fmtargs_logmesg(LAMMPS *lmp, fmt::string_view format, fmt::format_ar
 
 std::string utils::getsyserror()
 {
-  return std::string(strerror(errno));
+  return {strerror(errno)};
 }
 
 // read line into buffer. if line is too long keep reading until EOL or EOF
@@ -738,7 +738,7 @@ std::string utils::trim_comment(const std::string &line)
 {
   auto end = line.find_first_of('#');
   if (end != std::string::npos) { return line.substr(0, end); }
-  return std::string(line);
+  return {line};
 }
 
 /* ----------------------------------------------------------------------