Add support for unsigned integer conversions (#47)

* Added support for unsigned integer conversions

* Updated single header

* Fix uninitialized variable warning in test

README.md

@@ -144,7 +144,8 @@ for (auto& row: reader) {
 If your CSV has lots of numeric values, you can also have this parser (lazily)
 convert them to the proper data type.
 
- * Type checking is performed on conversions to prevent undefined behavior and integer overflow.
+ * Type checking is performed on conversions to prevent undefined behavior and integer overflow
+   * Negative numbers cannot be blindly converted to unsigned integer types
  * `get<float>()`, `get<double>()`, and `get<long double>()` are capable of parsing numbers written in scientific notation.
  * **Note:** Conversions to floating point types are not currently checked for loss of precision.
 
@@ -159,7 +160,8 @@ CSVReader reader("very_big_file.csv");
 
 for (auto& row: reader) {
     if (row["timestamp"].is_int()) {
-		// Can use get<>() with any signed integer type
+		// Can use get<>() with any integer type, but negative
+        // numbers cannot be converted to unsigned types
         row["timestamp"].get<int>();
         
         // ..

include/csv.hpp

@@ -1,5 +1,5 @@
 /*
-CSV for C++, version 1.2.0
+CSV for C++, version 1.2.1
 https://github.com/vincentlaucsb/csv-parser
 
 MIT License

include/internal/csv_row.hpp

@@ -22,11 +22,12 @@ namespace csv {
         static const std::string ERROR_OVERFLOW = "Overflow error.";
         static const std::string ERROR_FLOAT_TO_INT =
             "Attempted to convert a floating point value to an integral type.";
+        static const std::string ERROR_NEG_TO_UNSIGNED = "Negative numbers cannot be converted to unsigned types.";
     }
 
     /**
     * @class CSVField
-    * @brief Data type representing individual CSV values. 
+    * @brief Data type representing individual CSV values.
     *        CSVFields can be obtained by using CSVRow::operator[]
     */
     class CSVField {
@@ -66,19 +67,25 @@ namespace csv {
         *           numeric value.
         *
         */
-        template<typename T=std::string> T get() {
-            static_assert(!std::is_unsigned<T>::value, "Conversions to unsigned types are not supported.");
-
-            IF_CONSTEXPR (std::is_arithmetic<T>::value) {
+        template<typename T = std::string> T get() {
+            IF_CONSTEXPR(std::is_arithmetic<T>::value) {
+                // Note: this->type() also converts the CSV value to float
                 if (this->type() <= CSV_STRING) {
                     throw std::runtime_error(internals::ERROR_NAN);
                 }
             }
 
             IF_CONSTEXPR(std::is_integral<T>::value) {
+                // Note: this->is_float() also converts the CSV value to float
                 if (this->is_float()) {
                     throw std::runtime_error(internals::ERROR_FLOAT_TO_INT);
                 }
+
+                IF_CONSTEXPR(std::is_unsigned<T>::value) {
+                    if (this->value < 0) {
+                        throw std::runtime_error(internals::ERROR_NEG_TO_UNSIGNED);
+                    }
+                }
             }
 
             // Allow fallthrough from previous if branch
@@ -90,7 +97,7 @@ namespace csv {
 
             return static_cast<T>(this->value);
         }
-   
+
         /** Compares the contents of this field to a numeric value. If this
          *  field does not contain a numeric value, then all comparisons return
          *  false.
@@ -125,7 +132,7 @@ namespace csv {
 
             return internals::is_equal(out, static_cast<long double>(other), 0.000001L);
         }
-        
+
         /** Returns true if field is an empty string or string of whitespace characters */
         CONSTEXPR bool is_null() { return type() == CSV_NULL; }
 
@@ -179,7 +186,7 @@ namespace csv {
         };
 
         /** Constructor for testing */
-        CSVRow(const std::string& str, const std::vector<unsigned short>& splits, 
+        CSVRow(const std::string& str, const std::vector<unsigned short>& splits,
             const std::shared_ptr<internals::ColNames>& col_names)
             : CSVRow(internals::BufferPtr(new internals::RawRowBuffer(str, splits, col_names))) {};
 
@@ -207,21 +214,21 @@ namespace csv {
          */
         class iterator {
         public:
-            #ifndef DOXYGEN_SHOULD_SKIP_THIS
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
             using value_type = CSVField;
             using difference_type = int;
 
             // Using CSVField * as pointer type causes segfaults in MSVC debug builds
             // but using shared_ptr as pointer type won't compile in g++
-            #ifdef _MSC_BUILD
-            using pointer = std::shared_ptr<CSVField> ;
-            #else
+#ifdef _MSC_BUILD
+            using pointer = std::shared_ptr<CSVField>;
+#else
             using pointer = CSVField * ;
-            #endif
+#endif
 
             using reference = CSVField & ;
             using iterator_category = std::random_access_iterator_tag;
-            #endif
+#endif
 
             iterator(const CSVRow*, int i);
 
@@ -238,9 +245,9 @@ namespace csv {
             bool operator==(const iterator&) const;
             bool operator!=(const iterator& other) const { return !operator==(other); }
 
-            #ifndef NDEBUG
+#ifndef NDEBUG
             friend CSVRow;
-            #endif
+#endif
 
         private:
             const CSVRow * daddy = nullptr;            // Pointer to parent
@@ -254,7 +261,7 @@ namespace csv {
         /** @name Iterators
          *  @brief Each iterator points to a CSVField object.
          */
-        ///@{
+         ///@{
         iterator begin() const;
         iterator end() const;
         reverse_iterator rbegin() const;
@@ -265,8 +272,8 @@ namespace csv {
         /** Get the index in CSVRow's text buffer where the n-th field begins */
         unsigned short split_at(size_t n) const;
 
-		internals::BufferPtr buffer = nullptr; /**< Memory buffer containing data for this row. */
-		csv::string_view row_str = "";         /**< Text data for this row */
+        internals::BufferPtr buffer = nullptr; /**< Memory buffer containing data for this row. */
+        csv::string_view row_str = "";         /**< Text data for this row */
         size_t start;                          /**< Where in split buffer this row begins */
         unsigned short n_cols;                 /**< Numbers of columns this row has */
     };
@@ -280,7 +287,7 @@ namespace csv {
 
     /** Retrieve a view over this field's string
      *
-     *  @warning This string_view is only guaranteed to be valid as long as this 
+     *  @warning This string_view is only guaranteed to be valid as long as this
      *           CSVRow is still alive.
      */
     template<>

single_include/csv.hpp

@@ -1,6 +1,6 @@
 #pragma once
 /*
-CSV for C++, version 1.2.0
+CSV for C++, version 1.2.1
 https://github.com/vincentlaucsb/csv-parser
 
 MIT License
@@ -3717,11 +3717,12 @@ namespace csv {
         static const std::string ERROR_OVERFLOW = "Overflow error.";
         static const std::string ERROR_FLOAT_TO_INT =
             "Attempted to convert a floating point value to an integral type.";
+        static const std::string ERROR_NEG_TO_UNSIGNED = "Negative numbers cannot be converted to unsigned types.";
     }
 
     /**
     * @class CSVField
-    * @brief Data type representing individual CSV values. 
+    * @brief Data type representing individual CSV values.
     *        CSVFields can be obtained by using CSVRow::operator[]
     */
     class CSVField {
@@ -3761,19 +3762,25 @@ namespace csv {
         *           numeric value.
         *
         */
-        template<typename T=std::string> T get() {
-            static_assert(!std::is_unsigned<T>::value, "Conversions to unsigned types are not supported.");
-
-            IF_CONSTEXPR (std::is_arithmetic<T>::value) {
+        template<typename T = std::string> T get() {
+            IF_CONSTEXPR(std::is_arithmetic<T>::value) {
+                // Note: this->type() also converts the CSV value to float
                 if (this->type() <= CSV_STRING) {
                     throw std::runtime_error(internals::ERROR_NAN);
                 }
             }
 
             IF_CONSTEXPR(std::is_integral<T>::value) {
+                // Note: this->is_float() also converts the CSV value to float
                 if (this->is_float()) {
                     throw std::runtime_error(internals::ERROR_FLOAT_TO_INT);
                 }
+
+                IF_CONSTEXPR(std::is_unsigned<T>::value) {
+                    if (this->value < 0) {
+                        throw std::runtime_error(internals::ERROR_NEG_TO_UNSIGNED);
+                    }
+                }
             }
 
             // Allow fallthrough from previous if branch
@@ -3785,7 +3792,7 @@ namespace csv {
 
             return static_cast<T>(this->value);
         }
-   
+
         /** Compares the contents of this field to a numeric value. If this
          *  field does not contain a numeric value, then all comparisons return
          *  false.
@@ -3820,7 +3827,7 @@ namespace csv {
 
             return internals::is_equal(out, static_cast<long double>(other), 0.000001L);
         }
-        
+
         /** Returns true if field is an empty string or string of whitespace characters */
         CONSTEXPR bool is_null() { return type() == CSV_NULL; }
 
@@ -3874,7 +3881,7 @@ namespace csv {
         };
 
         /** Constructor for testing */
-        CSVRow(const std::string& str, const std::vector<unsigned short>& splits, 
+        CSVRow(const std::string& str, const std::vector<unsigned short>& splits,
             const std::shared_ptr<internals::ColNames>& col_names)
             : CSVRow(internals::BufferPtr(new internals::RawRowBuffer(str, splits, col_names))) {};
 
@@ -3902,21 +3909,21 @@ namespace csv {
          */
         class iterator {
         public:
-            #ifndef DOXYGEN_SHOULD_SKIP_THIS
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
             using value_type = CSVField;
             using difference_type = int;
 
             // Using CSVField * as pointer type causes segfaults in MSVC debug builds
             // but using shared_ptr as pointer type won't compile in g++
-            #ifdef _MSC_BUILD
-            using pointer = std::shared_ptr<CSVField> ;
-            #else
+#ifdef _MSC_BUILD
+            using pointer = std::shared_ptr<CSVField>;
+#else
             using pointer = CSVField * ;
-            #endif
+#endif
 
             using reference = CSVField & ;
             using iterator_category = std::random_access_iterator_tag;
-            #endif
+#endif
 
             iterator(const CSVRow*, int i);
 
@@ -3933,9 +3940,9 @@ namespace csv {
             bool operator==(const iterator&) const;
             bool operator!=(const iterator& other) const { return !operator==(other); }
 
-            #ifndef NDEBUG
+#ifndef NDEBUG
             friend CSVRow;
-            #endif
+#endif
 
         private:
             const CSVRow * daddy = nullptr;            // Pointer to parent
@@ -3949,7 +3956,7 @@ namespace csv {
         /** @name Iterators
          *  @brief Each iterator points to a CSVField object.
          */
-        ///@{
+         ///@{
         iterator begin() const;
         iterator end() const;
         reverse_iterator rbegin() const;
@@ -3960,8 +3967,8 @@ namespace csv {
         /** Get the index in CSVRow's text buffer where the n-th field begins */
         unsigned short split_at(size_t n) const;
 
-		internals::BufferPtr buffer = nullptr; /**< Memory buffer containing data for this row. */
-		csv::string_view row_str = "";         /**< Text data for this row */
+        internals::BufferPtr buffer = nullptr; /**< Memory buffer containing data for this row. */
+        csv::string_view row_str = "";         /**< Text data for this row */
         size_t start;                          /**< Where in split buffer this row begins */
         unsigned short n_cols;                 /**< Numbers of columns this row has */
     };
@@ -3975,7 +3982,7 @@ namespace csv {
 
     /** Retrieve a view over this field's string
      *
-     *  @warning This string_view is only guaranteed to be valid as long as this 
+     *  @warning This string_view is only guaranteed to be valid as long as this
      *           CSVRow is still alive.
      */
     template<>

tests/test_csv_field.cpp

@@ -59,6 +59,14 @@ TEST_CASE("CSVField get<>() - Integral Value", "[test_csv_field_get_int]") {
     REQUIRE(ex_caught);
 }
 
+// Test converting a small integer to unsigned and signed integer types
+TEMPLATE_TEST_CASE("CSVField get<>() - Integral Value to Int", "[test_csv_field_get_int]",
+    unsigned char, unsigned short, unsigned int, unsigned long long,
+    char, short, int, long long int) {
+    CSVField savage("21");
+    REQUIRE(savage.get<TestType>() == 21);
+}
+
 TEST_CASE("CSVField get<>() - Floating Point Value", "[test_csv_field_get_float]") {
     CSVField euler("2.718");
     REQUIRE(euler.get<>() == "2.718");
@@ -69,6 +77,7 @@ TEST_CASE("CSVField get<>() - Floating Point Value", "[test_csv_field_get_float]
 }
 
 TEMPLATE_TEST_CASE("CSVField get<>() - Disallow Float to Int", "[test_csv_field_get_float_as_int]",
+    unsigned char, unsigned short, unsigned int, unsigned long long int,
     signed char, short, int, long long int) {
     CSVField euler("2.718");
     bool ex_caught = false;
@@ -84,6 +93,22 @@ TEMPLATE_TEST_CASE("CSVField get<>() - Disallow Float to Int", "[test_csv_field_
     REQUIRE(ex_caught);
 }
 
+TEMPLATE_TEST_CASE("CSVField get<>() - Disallow Negative to Unsigned", "[test_csv_field_no_unsigned_neg]",
+    unsigned char, unsigned short, unsigned int, unsigned long long int) {
+    CSVField neg("-1337");
+    bool ex_caught = false;
+
+    try {
+        neg.get<TestType>();
+    }
+    catch (std::runtime_error& err) {
+        REQUIRE(err.what() == csv::internals::ERROR_NEG_TO_UNSIGNED);
+        ex_caught = true;
+    }
+
+    REQUIRE(ex_caught);
+}
+
 TEST_CASE("CSVField Equality Operator", "[test_csv_field_operator==]") {
     CSVField field("3.14");
     REQUIRE(field == "3.14");

tests/test_data_type.cpp

@@ -76,7 +76,7 @@ TEST_CASE( "Recognize Sub-Unit Double Values", "[regression_double]" ) {
 
 TEST_CASE( "Recognize Double Values", "[regression_double2]" ) {
     // Test converting double values back and forth
-    long double out;
+    long double out = -1.0;
     std::string s;
 
     for (long double i = 0; i <= 2.0; i += 0.01) {