From 1ebae5693cbc63b1c1ccffabd75673c08dfd146f Mon Sep 17 00:00:00 2001
From: Andrey Nefedov <ioxid@nil.foundation>
Date: Sat, 14 Dec 2024 22:07:18 +0000
Subject: [PATCH] multiprecision: big_uint: fix constructors from string-like
 types

---
 .../multiprecision/detail/big_uint/big_uint_impl.hpp   |  5 ++---
 .../multiprecision/detail/big_uint/type_traits.hpp     | 10 ++++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/big_uint_impl.hpp b/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/big_uint_impl.hpp
index 7d36cf875..0ec75d040 100644
--- a/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/big_uint_impl.hpp
+++ b/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/big_uint_impl.hpp
@@ -16,7 +16,6 @@
 #include <iostream>
 #include <stdexcept>
 #include <string>
-#include <string_view>
 #include <system_error>
 #include <type_traits>
 
@@ -156,7 +155,7 @@ namespace nil::crypto3::multiprecision {
 
         constexpr big_uint() noexcept {}
 
-        template<typename T, std::enable_if_t<std::is_convertible_v<T, std::string_view>, int> = 0>
+        template<typename T, std::enable_if_t<detail::is_supported_string_type_v<T>, int> = 0>
         constexpr big_uint(const T& str) {
             *this = str;
         }
@@ -188,7 +187,7 @@ namespace nil::crypto3::multiprecision {
 
         // Assignment
 
-        template<typename T, std::enable_if_t<std::is_convertible_v<T, std::string_view>, int> = 0>
+        template<typename T, std::enable_if_t<detail::is_supported_string_type_v<T>, int> = 0>
         constexpr big_uint& operator=(const T& str) {
             *this = detail::parse_int<Bits>(str);
             return *this;
diff --git a/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/type_traits.hpp b/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/type_traits.hpp
index 412b00533..fd97efc30 100644
--- a/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/type_traits.hpp
+++ b/crypto3/libs/multiprecision/include/nil/crypto3/multiprecision/detail/big_uint/type_traits.hpp
@@ -3,6 +3,8 @@
 #include <algorithm>
 #include <climits>
 #include <cstddef>
+#include <string>
+#include <string_view>
 #include <type_traits>
 
 #include "nil/crypto3/multiprecision/detail/big_uint/storage.hpp"
@@ -21,6 +23,14 @@ namespace nil::crypto3::multiprecision {
         template<typename T>
         constexpr bool is_integral_v = std::is_integral_v<T> || is_big_uint_v<T>;
 
+        template<typename T>
+        constexpr bool is_supported_string_type_v =
+            (std::is_array_v<T> &&
+             std::is_same_v<std::remove_cv_t<std::remove_extent_t<T>>, char>) ||
+            (std::is_pointer_v<T> &&
+             (std::is_same_v<std::remove_cv_t<std::remove_pointer_t<T>>, char>)) ||
+            std::is_same_v<T, std::string_view> || std::is_same_v<T, std::string>;
+
         template<typename T, std::enable_if_t<std::is_integral_v<T>, int> = 0>
         constexpr std::size_t get_bits() {
             return sizeof(T) * CHAR_BIT;