diff --git a/CMakeLists.txt b/CMakeLists.txt
index 72737549..16ae2f92 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -83,6 +83,13 @@ if(OMPPARSER_ENABLE_WASM)
   add_subdirectory(wasm)
 endif()
 
+if(BUILD_TESTING)
+  add_custom_target(check
+    COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure
+    DEPENDS tester omp_roundtrip test_locations
+    COMMENT "Running all tests...")
+endif()
+
 set(ompparser_targets ompparser)
 
 # Install headers and libraries
diff --git a/src/OpenMPIR.cpp b/src/OpenMPIR.cpp
index 053237d0..3dbe4ee7 100644
--- a/src/OpenMPIR.cpp
+++ b/src/OpenMPIR.cpp
@@ -62,6 +62,23 @@ std::string trimWhitespace(const std::string &text) {
   return text.substr(begin, end - begin + 1);
 }
 
+std::string trimWhitespace(const std::string &text, size_t pos, size_t count) {
+  if (pos >= text.size()) {
+    return std::string();
+  }
+  const char *whitespace = " \t\n\r\f\v";
+  size_t end_pos = pos + count;
+  if (end_pos > text.size() || end_pos < pos) {
+    end_pos = text.size();
+  }
+  size_t begin = text.find_first_not_of(whitespace, pos);
+  if (begin == std::string::npos || begin >= end_pos) {
+    return std::string();
+  }
+  size_t end = text.find_last_not_of(whitespace, end_pos - 1);
+  return text.substr(begin, end - begin + 1);
+}
+
 std::string normalizeRawExpression(const char *expr,
                                    bool strip_trailing_colon = false) {
   if (!expr) {
@@ -181,15 +198,6 @@ std::string normalizeClauseExpression(OpenMPClauseKind kind,
 
 namespace {
 
-std::string trimWhitespaceCopy(const std::string &value) {
-  const std::string::size_type begin = value.find_first_not_of(" \t\r\n");
-  if (begin == std::string::npos) {
-    return std::string();
-  }
-  const std::string::size_type end = value.find_last_not_of(" \t\r\n");
-  return value.substr(begin, end - begin + 1);
-}
-
 bool isIdentifierChar(char ch) {
   const unsigned char uch = static_cast<unsigned char>(ch);
   return std::isalnum(uch) != 0 || ch == '_';
@@ -284,7 +292,7 @@ bool hasIncompleteTrailingOperator(const std::string &expression) {
 }
 
 bool isValidDistDataBaseExpression(const std::string &expression) {
-  const std::string trimmed_expression = trimWhitespaceCopy(expression);
+  const std::string trimmed_expression = trimWhitespace(expression);
   if (trimmed_expression.empty()) {
     return false;
   }
@@ -349,7 +357,7 @@ bool splitMapExpressionDistDataSuffix(const std::string &expression,
     return false;
   }
 
-  const std::string trimmed_expression = trimWhitespaceCopy(expression);
+  const std::string trimmed_expression = trimWhitespace(expression);
   *array_section_expression = trimmed_expression;
   dist_data_arguments->clear();
   if (trimmed_expression.empty() || trimmed_expression.back() != ')') {
@@ -408,7 +416,7 @@ bool splitMapExpressionDistDataSuffix(const std::string &expression,
   }
 
   const std::string prefix =
-      trimWhitespaceCopy(trimmed_expression.substr(0, open_paren_pos));
+      trimWhitespace(trimmed_expression, 0, open_paren_pos);
   if (prefix.empty()) {
     return false;
   }
@@ -442,14 +450,14 @@ bool splitMapExpressionDistDataSuffix(const std::string &expression,
   }
 
   const std::string base_expression =
-      trimWhitespaceCopy(prefix.substr(0, token_begin));
+      trimWhitespace(prefix, 0, token_begin);
   if (!isValidDistDataBaseExpression(base_expression)) {
     return false;
   }
 
   *array_section_expression = base_expression;
-  *dist_data_arguments = trimWhitespaceCopy(trimmed_expression.substr(
-      open_paren_pos + 1, trimmed_expression.size() - open_paren_pos - 2));
+  *dist_data_arguments = trimWhitespace(trimmed_expression, open_paren_pos + 1,
+      trimmed_expression.size() - open_paren_pos - 2);
   return true;
 }
 
@@ -863,7 +871,7 @@ void OpenMPMapClause::addItem(const std::string &expr,
   bool has_dist_data = splitMapExpressionDistDataSuffix(
       expr, &array_section_expression, &dist_data_arguments);
 
-  const std::string trimmed_expression = trimWhitespaceCopy(expr);
+  const std::string trimmed_expression = trimWhitespace(expr);
   std::string item_expression = trimmed_expression;
   if (has_dist_data) {
     item_expression = array_section_expression + " dist_data(" +
@@ -881,7 +889,7 @@ void OpenMPMapClause::addItem(const std::string &expr,
     const std::vector<std::string> policy_texts =
         splitTopLevelCommaSeparated(dist_data_arguments);
     for (const std::string &raw_policy : policy_texts) {
-      const std::string policy_text = trimWhitespaceCopy(raw_policy);
+      const std::string policy_text = trimWhitespace(raw_policy);
       if (policy_text.empty()) {
         continue;
       }
@@ -907,12 +915,12 @@ void OpenMPMapClause::addItem(const std::string &expr,
           }
         }
         if (close_pos == std::string::npos ||
-            trimWhitespaceCopy(policy_text.substr(close_pos + 1)).size() != 0) {
+            trimWhitespace(policy_text, close_pos + 1, policy_text.size() - close_pos - 1).size() != 0) {
           continue;
         }
-        policy_name = trimWhitespaceCopy(policy_text.substr(0, open_pos));
-        policy_argument = trimWhitespaceCopy(
-            policy_text.substr(open_pos + 1, close_pos - open_pos - 1));
+        policy_name = trimWhitespace(policy_text, 0, open_pos);
+        policy_argument = trimWhitespace(
+            policy_text, open_pos + 1, close_pos - open_pos - 1);
       }
 
       std::string normalized_name = policy_name;
diff --git a/src/OpenMPIR.h b/src/OpenMPIR.h
index 4fedae67..31af4025 100644
--- a/src/OpenMPIR.h
+++ b/src/OpenMPIR.h
@@ -22,8 +22,6 @@
 #include <string>
 #include <vector>
 
-using namespace std;
-
 enum OpenMPBaseLang { Lang_C, Lang_Cplusplus, Lang_Fortran, Lang_unknown };
 
 enum OpenMPExprParseMode {
@@ -211,7 +209,7 @@ class OpenMPDirective : public SourceLocation {
    * should only have one OpenMPClause object for each instance of kind and full
    * parameters
    */
-  map<OpenMPClauseKind, vector<OpenMPClause *> *> clauses;
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> clauses;
 
   // Owned storage for clause objects to ensure automatic cleanup
   std::vector<std::unique_ptr<OpenMPClause>> clause_storage;
@@ -270,7 +268,7 @@ class OpenMPDirective : public SourceLocation {
 
   OpenMPDirectiveKind getKind() { return kind; };
 
-  map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *getAllClauses() {
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *getAllClauses() {
     return &clauses;
   };
 
@@ -320,8 +318,8 @@ class OpenMPDirective : public SourceLocation {
 // atomic directive
 class OpenMPAtomicDirective : public OpenMPDirective {
 protected:
-  map<OpenMPClauseKind, vector<OpenMPClause *> *> clauses_atomic_after;
-  map<OpenMPClauseKind, vector<OpenMPClause *> *> clauses_atomic_clauses;
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> clauses_atomic_after;
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> clauses_atomic_clauses;
   std::vector<std::unique_ptr<std::vector<OpenMPClause *>>>
       atomic_clause_vector_storage;
 
@@ -343,11 +341,11 @@ class OpenMPAtomicDirective : public OpenMPDirective {
     }
     return clauses_atomic_clauses[kind];
   };
-  map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *
   getAllClausesAtomicAfter() {
     return &clauses_atomic_after;
   };
-  map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *getAllAtomicClauses() {
+  std::map<OpenMPClauseKind, std::vector<OpenMPClause *> *> *getAllAtomicClauses() {
     return &clauses_atomic_clauses;
   };
 };