replace substr with resize/pop_back

Shorter and more efficient.

Signed-off-by: Rosen Penev <[email protected]>

app/actions.cpp

@@ -631,7 +631,7 @@ int Rename::run(const std::string& path) {
       return 1;
     }
     std::string v = md->toString();
-    if (v.length() == 0 || v[0] == ' ') {
+    if (v.empty() || v.front() == ' ') {
       std::cerr << _("Image file creation timestamp not set in the file") << " " << path << "\n";
       return 1;
     }
@@ -1602,7 +1602,7 @@ int Timestamp::touch(const std::string& path) const {
 //! @endcond
 
 int str2Tm(const std::string& timeStr, struct tm* tm) {
-  if (timeStr.length() == 0 || timeStr[0] == ' ')
+  if (timeStr.empty() || timeStr.front() == ' ')
     return 1;
   if (timeStr.length() < 19)
     return 2;

src/convert.cpp

@@ -740,7 +740,7 @@ void Converter::cnvExifDate(const char* from, const char* to) {
   }
 
   if (subsec.size() > 10)
-    subsec = subsec.substr(0, 10);
+    subsec.resize(10);
   snprintf(buf, sizeof(buf), "%4d-%02d-%02dT%02d:%02d:%02d%s", year, month, day, hour, min, sec, subsec.c_str());
   buf[sizeof(buf) - 1] = 0;
 
@@ -1141,7 +1141,7 @@ void Converter::cnvXmpGPSCoord(const char* from, const char* to) {
   double deg = 0.0;
   double min = 0.0;
   double sec = 0.0;
-  char ref = value[value.length() - 1];
+  char ref = value.back();
   char sep1 = '\0';
   char sep2 = '\0';
 

src/http.cpp

@@ -305,8 +305,8 @@ int Exiv2::http(Exiv2::Dictionary& request, Exiv2::Dictionary& response, std::st
         while (c && first_newline && c < first_newline && h < buffer + body) {
           std::string key(h);
           std::string value(c + 1);
-          key = key.substr(0, c - h);
-          value = value.substr(0, first_newline - c - 1);
+          key.resize(c - h);
+          value.resize(first_newline - c - 1);
           response[key] = value;
           h = first_newline + 1;
           c = strchr(h, C);

src/pngimage.cpp

@@ -247,7 +247,7 @@ void PngImage::printStructure(std::ostream& out, PrintStructureOption option, si
       }
       while (dataString.size() < iMax)
         dataString += ' ';
-      dataString = dataString.substr(0, iMax);
+      dataString.resize(iMax);
 
       if (bPrint) {
         io_->seek(dataOffset, BasicIo::cur);  // jump to checksum

src/value.cpp

@@ -325,8 +325,8 @@ int CommentValue::read(const std::string& comment) {
     // Strip quotes (so you can also specify the charset without quotes)
     if (!name.empty() && name.front() == '"')
       name = name.substr(1);
-    if (!name.empty() && name[name.length() - 1] == '"')
-      name = name.substr(0, name.length() - 1);
+    if (!name.empty() && name.back() == '"')
+      name.pop_back();
     charsetId = CharsetInfo::charsetIdByName(name);
     if (charsetId == invalidCharsetId) {
 #ifndef SUPPRESS_WARNINGS
@@ -391,7 +391,7 @@ std::string CommentValue::comment(const char* encoding) const {
   bool bAscii = charsetId() == undefined || charsetId() == ascii;
   // # 1266 Remove trailing nulls
   if (bAscii && c.find('\0') != std::string::npos) {
-    c = c.substr(0, c.find('\0'));
+    c.resize(c.find('\0'));
   }
   return c;
 }
@@ -503,8 +503,8 @@ int XmpTextValue::read(const std::string& buf) {
     // Strip quotes (so you can also specify the type without quotes)
     if (!type.empty() && type.front() == '"')
       type = type.substr(1);
-    if (!type.empty() && type[type.length() - 1] == '"')
-      type = type.substr(0, type.length() - 1);
+    if (!type.empty() && type.back() == '"')
+      type.pop_back();
     b.clear();
     if (pos != std::string::npos)
       b = buf.substr(pos + 1);
@@ -670,7 +670,7 @@ int LangAltValue::read(const std::string& buf) {
       if (lang.empty() || lang.find('"') != lang.length() - 1)
         throw Error(ErrorCode::kerInvalidLangAltValue, buf);
 
-      lang = lang.substr(0, lang.length() - 1);
+      lang.pop_back();
     }
 
     if (lang.empty())

src/xmp.cpp

@@ -585,11 +585,8 @@ static XMP_Status nsDumper(void* refCon, XMP_StringPtr buffer, XMP_StringLen buf
   bool bNS = out.find(':') != std::string::npos && !bURI;
 
   // pop trailing ':' on a namespace
-  if (bNS && !out.empty()) {
-    std::size_t length = out.length();
-    if (out[length - 1] == ':')
-      out = out.substr(0, length - 1);
-  }
+  if (bNS && !out.empty() && out.back() == ':')
+    out.pop_back();
 
   if (bURI || bNS) {
     auto p = static_cast<std::map<std::string, std::string>*>(refCon);
@@ -706,7 +703,7 @@ int XmpParser::decode(XmpData& xmpData, const std::string& xmpPacket) {
           bool ret = SXMPMeta::GetNamespacePrefix(schemaNs.c_str(), &prefix);
           if (!ret)
             throw Error(ErrorCode::kerSchemaNamespaceNotRegistered, schemaNs);
-          prefix = prefix.substr(0, prefix.size() - 1);
+          prefix.pop_back();
           XmpProperties::registerNs(schemaNs, prefix);
         }
         continue;