diff --git a/six/modules/c++/cphd03/source/CPHDXMLControl.cpp b/six/modules/c++/cphd03/source/CPHDXMLControl.cpp
index 38d3d35bc..1bda52ef8 100644
--- a/six/modules/c++/cphd03/source/CPHDXMLControl.cpp
+++ b/six/modules/c++/cphd03/source/CPHDXMLControl.cpp
@@ -778,8 +778,7 @@ void CPHDXMLControl::fromXML(const xml::lite::Element* srpXML, SRP& srp)
 #if ENFORCESPEC
     srp.srpType = cphd::SRPType(getFirstAndOnly(srpXML, "SRPType")->getCharacterData());
 #else
-    std::string s(getFirstAndOnly(srpXML, "SRPType")->getCharacterData());
-    str::upper(s);
+    const auto s = str::upper(getFirstAndOnly(srpXML, "SRPType")->getCharacterData());
     srp.srpType = cphd::SRPType::toType(s);
 #endif
     parseInt(getFirstAndOnly(srpXML, "NumSRPs"), srp.numSRPs);
diff --git a/six/modules/c++/samples/check_valid_six.cpp b/six/modules/c++/samples/check_valid_six.cpp
index c1f7e6ea4..2f4bac8c6 100644
--- a/six/modules/c++/samples/check_valid_six.cpp
+++ b/six/modules/c++/samples/check_valid_six.cpp
@@ -189,7 +189,7 @@ static int main_(int argc, char** argv)
     const std::string inputPath(options->get<std::string>("input"));
     std::vector<std::string> inputPathnames = getPathnames(inputPath);
     const std::string logFile(options->get<std::string>("log"));
-    std::string level(options->get<std::string>("level"));
+    auto level = str::upper(options->get<std::string>("level"));
     std::vector<std::string> schemaPaths;
     getSchemaPaths(*options, "--schema", "schema", schemaPaths);
 
@@ -200,7 +200,6 @@ static int main_(int argc, char** argv)
     xmlRegistry.addCreator<six::sicd::ComplexXMLControl>();
     xmlRegistry.addCreator<six::sidd::DerivedXMLControl>();
 
-    str::upper(level);
     str::trim(level);
     std::unique_ptr<logging::Logger> log =
         logging::setupLogger(fs::path(argv[0]).filename().string(), level, logFile);
diff --git a/six/modules/c++/six.sicd/source/Grid.cpp b/six/modules/c++/six.sicd/source/Grid.cpp
index 9f5577018..ea6805336 100644
--- a/six/modules/c++/six.sicd/source/Grid.cpp
+++ b/six/modules/c++/six.sicd/source/Grid.cpp
@@ -132,14 +132,13 @@ DirectionParameters::calculateWeightFunction() const
         return nullptr;
     }
 
-    std::string windowName(weightType->windowName);
-    str::upper(windowName);
+    const std::string windowName(weightType->windowName);
 
-    if (windowName == "UNIFORM")
+    if (str::eq(windowName, "UNIFORM"))
     {
         return std::make_unique<Identity>();
     }
-    if (windowName == "HAMMING")
+    if (str::eq(windowName, "HAMMING"))
     {
         double coef = 0.0;
         if (weightType->parameters.empty() || weightType->parameters[0].str().empty())
@@ -156,11 +155,11 @@ DirectionParameters::calculateWeightFunction() const
 
         return std::make_unique<RaisedCos>(coef);
     }
-    if (windowName == "HANNING")
+    if (str::eq(windowName, "HANNING"))
     {
         return std::make_unique<RaisedCos>(0.50);
     }
-    if (windowName == "KAISER")
+    if (str::eq(windowName, "KAISER"))
     {
         return std::make_unique<Kaiser>(double(weightType->parameters[0]));
     }
diff --git a/six/modules/c++/six.sicd/source/Utilities.cpp b/six/modules/c++/six.sicd/source/Utilities.cpp
index 039c528c2..5dd9e3483 100644
--- a/six/modules/c++/six.sicd/source/Utilities.cpp
+++ b/six/modules/c++/six.sicd/source/Utilities.cpp
@@ -717,10 +717,8 @@ std::unique_ptr<ComplexData> Utilities::getComplexData(
         const std::string& pathname,
         const std::vector<std::string>& schemaPaths)
 {
-    std::string extension = fs::path(pathname).extension().string();
-    str::lower(extension);
-
-    if (extension == ".xml")
+    const auto extension = fs::path(pathname).extension().string();
+    if (str::eq(extension, ".xml"))
     {
         logging::NullLogger log;
         return parseDataFromFile(pathname, schemaPaths, log);
diff --git a/six/modules/c++/six/source/Utilities.cpp b/six/modules/c++/six/source/Utilities.cpp
index 52d688375..ff04dd92c 100644
--- a/six/modules/c++/six/source/Utilities.cpp
+++ b/six/modules/c++/six/source/Utilities.cpp
@@ -96,10 +96,9 @@ BooleanType six::toType<BooleanType>(const std::string& s)
 {
     std::string type(s);
     str::trim(type);
-    str::lower(type);
-    if (type == "true" || type == "1" || type == "yes")
+    if (str::eq(type, "true") || type == "1" || str::eq(type, "yes"))
         return BooleanType::IS_TRUE;
-    if (type == "false" || type == "0" || type == "no")
+    if (str::eq(type, "false") || type == "0" || str::eq(type, "no"))
         return BooleanType::IS_FALSE;
     return BooleanType::NOT_SET;
 }