Issue276 plus/minus handling in parse_infnan

CONTRIBUTORS

@@ -8,3 +8,4 @@ Lénárd Szolnoki
 Jan Pharago
 Maya Warrier
 Taha Khokhar
+Anders Dalvander

include/fast_float/ascii_number.h

@@ -476,7 +476,7 @@ parse_int_string(UC const *p, UC const *pend, T &value, int base) {
 
   UC const *const first = p;
 
-  bool negative = (*p == UC('-'));
+  bool const negative = (*p == UC('-'));
   if (!std::is_signed<T>::value && negative) {
     answer.ec = std::errc::invalid_argument;
     answer.ptr = first;

include/fast_float/parse_number.h

@@ -25,18 +25,16 @@ from_chars_result_t<UC> FASTFLOAT_CONSTEXPR14 parse_infnan(UC const *first,
   from_chars_result_t<UC> answer{};
   answer.ptr = first;
   answer.ec = std::errc(); // be optimistic
-  bool minusSign = false;
-  if (*first ==
-      UC('-')) { // assume first < last, so dereference without checks;
-                 // C++17 20.19.3.(7.1) explicitly forbids '+' here
-    minusSign = true;
-    ++first;
-  }
+  // assume first < last, so dereference without checks;
+  bool const minusSign = (*first == UC('-'));
 #ifdef FASTFLOAT_ALLOWS_LEADING_PLUS // disabled by default
-  if (*first == UC('+')) {
+  if ((*first == UC('-')) || (*first == UC('+'))) {
+#else
+  // C++17 20.19.3.(7.1) explicitly forbids '+' sign here
+  if (*first == UC('-')) {
+#endif
     ++first;
   }
-#endif
   if (last - first >= 3) {
     if (fastfloat_strncasecmp(first, str_const_nan<UC>(), 3)) {
       answer.ptr = (first += 3);
@@ -93,7 +91,7 @@ fastfloat_really_inline bool rounds_to_nearest() noexcept {
   // However, it is expected to be much faster than the fegetround()
   // function call.
   //
-  // The volatile keywoard prevents the compiler from computing the function
+  // The volatile keyword prevents the compiler from computing the function
   // at compile-time.
   // There might be other ways to prevent compile-time optimizations (e.g.,
   // asm). The value does not need to be std::numeric_limits<float>::min(), any

tests/rcppfastfloat_test.cpp

@@ -41,7 +41,10 @@ bool eddelbuettel() {
                                      "-.1",
                                      "+.1",
                                      "1e+1",
-                                     "+1e1"};
+                                     "+1e1",
+                                     "-+0",
+                                     "-+inf",
+                                     "-+nan"};
   std::vector<std::pair<bool, double>> expected_results = {
       {true, std::numeric_limits<double>::infinity()},
       {true, 3.16227766016838},
@@ -75,6 +78,9 @@ bool eddelbuettel() {
       {true, 0.1},
       {true, 10},
       {true, 10},
+      {false, -1},
+      {false, -1},
+      {false, -1},
   };
   for (size_t i = 0; i < inputs.size(); i++) {
     const std::string &input = inputs[i];