Allow trailing spaces on strings for conversions (#1115)

Allow trailing spaces on strings for conversions to floating point and
integers.

There was a potential confusing error that could occur if strings with
trailing spaces were converted to integer or floating point values. This
PR allows trailing spaces in the strings that would otherwise be
convertible to the appropriate numerical type.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

include/CLI/TypeTools.hpp

@@ -968,6 +968,9 @@ bool integral_conversion(const std::string &input, T &output) noexcept {
         nstring.erase(std::remove(nstring.begin(), nstring.end(), '\''), nstring.end());
         return integral_conversion(nstring, output);
     }
+    if(std::isspace(static_cast<unsigned char>(input.back()))) {
+        return integral_conversion(trim_copy(input), output);
+    }
     if(input.compare(0, 2, "0o") == 0 || input.compare(0, 2, "0O") == 0) {
         val = nullptr;
         errno = 0;
@@ -1016,13 +1019,16 @@ bool integral_conversion(const std::string &input, T &output) noexcept {
         output = static_cast<T>(1);
         return true;
     }
-    // remove separators
+    // remove separators and trailing spaces
     if(input.find_first_of("_'") != std::string::npos) {
         std::string nstring = input;
         nstring.erase(std::remove(nstring.begin(), nstring.end(), '_'), nstring.end());
         nstring.erase(std::remove(nstring.begin(), nstring.end(), '\''), nstring.end());
         return integral_conversion(nstring, output);
     }
+    if(std::isspace(static_cast<unsigned char>(input.back()))) {
+        return integral_conversion(trim_copy(input), output);
+    }
     if(input.compare(0, 2, "0o") == 0 || input.compare(0, 2, "0O") == 0) {
         val = nullptr;
         errno = 0;
@@ -1147,6 +1153,13 @@ bool lexical_cast(const std::string &input, T &output) {
     if(val == (input.c_str() + input.size())) {
         return true;
     }
+    while(std::isspace(static_cast<unsigned char>(*val))) {
+        ++val;
+        if(val == (input.c_str() + input.size())) {
+            return true;
+        }
+    }
+
     // remove separators
     if(input.find_first_of("_'") != std::string::npos) {
         std::string nstring = input;

tests/OptionTypeTest.cpp

@@ -227,9 +227,13 @@ TEST_CASE_METHOD(TApp, "atomic_int_option", "[optiontype]") {
 static const std::map<std::string, double> testValuesDouble{
     {"3.14159", 3.14159},
     {"-3.14159", -3.14159},
+    {"-3.14159\t", -3.14159},
+    {"-3.14159  ", -3.14159},
     {"+1.0", 1.0},
     {"-0.01", -0.01},
     {"5e22", 5e22},
+    {" 5e22", 5e22},
+    {" 5e22  ", 5e22},
     {"-2E-2", -2e-2},
     {"5e+22", 5e22},
     {"1e06", 1e6},
@@ -268,6 +272,7 @@ static const std::map<std::string, std::int64_t> testValuesInt{
     {"+99", 99},
     {"99", 99},
     {"-99", -99},
+    {"-99 ", -99},
     {"0xDEADBEEF", 0xDEADBEEF},
     {"0xdeadbeef", 0xDEADBEEF},
     {"0XDEADBEEF", 0xDEADBEEF},
@@ -280,6 +285,7 @@ static const std::map<std::string, std::int64_t> testValuesInt{
     {"995862_262", 995862262},
     {"995862262", 995862262},
     {"-995862275", -995862275},
+    {"\t-995862275\t", -995862275},
     {"-995'862'275", -995862275},
     {"0b11010110", 0xD6},
     {"0b1101'0110", 0xD6},
@@ -323,6 +329,7 @@ TEST_CASE_METHOD(TApp, "intConversionsErange", "[optiontype]") {
 static const std::map<std::string, std::uint64_t> testValuesUInt{
     {"+99", 99},
     {"99", 99},
+    {" 99 ", 99},
     {"0xDEADBEEF", 0xDEADBEEF},
     {"0xdeadbeef", 0xDEADBEEF},
     {"0XDEADBEEF", 0xDEADBEEF},
@@ -331,13 +338,16 @@ static const std::map<std::string, std::uint64_t> testValuesUInt{
     {"0xdead'beef", 0xDEADBEEF},
     {"0o01234567", 001234567},
     {"0o755", 0755},
+    {"0o755\t", 0755},
     {"0755", 0755},
     {"995862_262", 995862262},
     {"995862262", 995862262},
     {"+995862275", +995862275},
+    {"+995862275         \n\t", +995862275},
     {"995'862'275", 995862275},
     {"0b11010110", 0xD6},
     {"0b1101'0110", 0xD6},
+    {"0b1101'0110                                                       ", 0xD6},
     {"0B11010110", 0xD6},
     {"0B1101'0110", 0xD6},
     {"1_2_3_4_5", 12345},