Fix ambiguous overloads on 32-bit platforms

On the 32-bit platforms in CI (windows and emscripten) large_int_t and
large_uint_t seem to alias each other in function definitions. Fix this by
using signed/unsigned concepts for the parameter. That way the incorrect
function will not be considered.

This required small bug fix in snitch::concepts. signed_integral and
unsigned_integral concepts need to check for sign and also make sure the
type is integral so that floating point or other types are not considered.

include/snitch/snitch_append.hpp

@@ -45,13 +45,13 @@ SNITCH_EXPORT [[nodiscard]] bool append_fast(small_string_span ss, double f) noe
     return could_fit;
 }
 
-template<large_uint_t Base = 10u>
-[[nodiscard]] constexpr std::size_t num_digits(large_uint_t x) noexcept {
+template<large_uint_t Base = 10u, unsigned_integral T>
+[[nodiscard]] constexpr std::size_t num_digits(T x) noexcept {
     return x >= Base ? 1u + num_digits<Base>(x / Base) : 1u;
 }
 
-template<large_int_t Base = 10>
-[[nodiscard]] constexpr std::size_t num_digits(large_int_t x) noexcept {
+template<large_int_t Base = 10, signed_integral T>
+[[nodiscard]] constexpr std::size_t num_digits(T x) noexcept {
     return (x >= Base || x <= -Base) ? 1u + num_digits<Base>(x / Base) : x > 0 ? 1u : 2u;
 }
 
@@ -61,8 +61,8 @@ constexpr std::array<char, 16> digits = {'0', '1', '2', '3', '4', '5', '6', '7',
 constexpr std::size_t max_uint_length = num_digits(std::numeric_limits<large_uint_t>::max());
 constexpr std::size_t max_int_length  = max_uint_length + 1;
 
-template<large_uint_t Base = 10u>
-[[nodiscard]] constexpr bool append_constexpr(small_string_span ss, large_uint_t i) noexcept {
+template<large_uint_t Base = 10u, unsigned_integral T>
+[[nodiscard]] constexpr bool append_constexpr(small_string_span ss, T i) noexcept {
     if (i != 0u) {
         small_string<max_uint_length> tmp;
         tmp.resize(num_digits<Base>(i));
@@ -76,8 +76,8 @@ template<large_uint_t Base = 10u>
     }
 }
 
-template<large_int_t Base = 10>
-[[nodiscard]] constexpr bool append_constexpr(small_string_span ss, large_int_t i) noexcept {
+template<large_int_t Base = 10, signed_integral T>
+[[nodiscard]] constexpr bool append_constexpr(small_string_span ss, T i) noexcept {
     if (i > 0) {
         small_string<max_int_length> tmp;
         tmp.resize(num_digits<Base>(i));

include/snitch/snitch_concepts.hpp

@@ -6,14 +6,15 @@
 #include <type_traits>
 
 namespace snitch {
+
 template<typename T>
-concept signed_integral = std::is_signed_v<T>;
+concept integral = std::is_integral_v<T>;
 
 template<typename T>
-concept unsigned_integral = std::is_unsigned_v<T>;
+concept signed_integral = integral<T> && std::is_signed_v<T>;
 
 template<typename T>
-concept integral = std::is_integral_v<T>;
+concept unsigned_integral = integral<T> && std::is_unsigned_v<T>;
 
 template<typename T>
 concept floating_point = std::is_floating_point_v<T>;