From 16992622e9a1cb43d771b3fdc597ebb367b60ac1 Mon Sep 17 00:00:00 2001
From: ckormanyos <ckormanyos@yahoo.com>
Date: Sat, 6 Sep 2025 13:51:02 +0200
Subject: [PATCH] Clarify matters of syntax

---
 .../boost/multiprecision/cpp_dec_float.hpp    | 13 +++++-
 test/git_issue_734.cpp                        | 40 ++++++++++++++-----
 2 files changed, 40 insertions(+), 13 deletions(-)

diff --git a/include/boost/multiprecision/cpp_dec_float.hpp b/include/boost/multiprecision/cpp_dec_float.hpp
index e9ae39f5..79bf0a5a 100644
--- a/include/boost/multiprecision/cpp_dec_float.hpp
+++ b/include/boost/multiprecision/cpp_dec_float.hpp
@@ -1932,8 +1932,17 @@ std::string cpp_dec_float<Digits10, ExponentType, Allocator>::str(std::intmax_t
    }
    else if (f & std::ios_base::scientific)
       ++number_of_digits;
-   // Determine the number of elements needed to provide the requested digits from cpp_dec_float<Digits10, ExponentType, Allocator>.
-   const std::size_t number_of_elements = (std::min)(static_cast<std::size_t>(static_cast<std::size_t>(number_of_digits / static_cast<std::intmax_t>(cpp_dec_float_elem_digits10)) + 2u),
+
+   // Determine the number of elements needed to provide the requested
+   // digits from cpp_dec_float<Digits10, ExponentType, Allocator>.
+   const std::intmax_t
+      number_of_elements_signed
+      {
+         (std::max)(static_cast<std::intmax_t>(number_of_digits / static_cast<std::intmax_t>(cpp_dec_float_elem_digits10) + 2),
+                    std::intmax_t { INT8_C(0) })
+      };
+
+   const std::size_t number_of_elements = (std::min)(static_cast<std::size_t>(number_of_elements_signed),
                                                      static_cast<std::size_t>(cpp_dec_float_elem_number));
 
    // Extract the remaining digits from cpp_dec_float<Digits10, ExponentType, Allocator> after the decimal point.
diff --git a/test/git_issue_734.cpp b/test/git_issue_734.cpp
index 10fc2ce7..77eb1be9 100644
--- a/test/git_issue_734.cpp
+++ b/test/git_issue_734.cpp
@@ -10,6 +10,7 @@
 #include <iomanip>
 #include <iostream>
 #include <sstream>
+#include <typeinfo>
 
 namespace local {
 
@@ -18,11 +19,17 @@ auto my_stringify_via_top_level_number(const std::streamsize strm_size) -> std::
 {
   using float_type = boost::multiprecision::number<BackendType, boost::multiprecision::et_off>;
 
+  #if defined(BOOST_MSVC)
+  using streamsize_type = std::streamsize;
+  #else
+  using streamsize_type = int;
+  #endif
+
   float_type x("0.0000000000000000222222222222222");
 
   std::stringstream strm { };
 
-  strm << std::setprecision(strm_size) << std::fixed;
+  strm << std::setprecision(static_cast<streamsize_type>(strm_size)) << std::fixed;
   strm << x;
 
   return strm.str();
@@ -33,11 +40,17 @@ auto my_stringify_via_str_and_backend_str(const std::streamsize strm_size) -> st
 {
   using float_type = boost::multiprecision::number<BackendType, boost::multiprecision::et_off>;
 
+  #if defined(BOOST_MSVC)
+  using streamsize_type = std::streamsize;
+  #else
+  using streamsize_type = int;
+  #endif
+
   float_type x("0.0000000000000000222222222222222");
 
   std::stringstream strm { };
 
-  strm << std::setprecision(strm_size) << std::fixed;
+  strm << std::setprecision(static_cast<streamsize_type>(strm_size)) << std::fixed;
 
   return x.str(strm_size, strm.flags());
 }
@@ -45,15 +58,17 @@ auto my_stringify_via_str_and_backend_str(const std::streamsize strm_size) -> st
 template<typename BackendType>
 auto test() -> void
 {
-  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(0)  == "0");
-  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(8)  == "0.00000000");
-  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(12) == "0.000000000000");
-  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(31) == "0.0000000000000000222222222222222");
+  std::cout << "Testing type of test: " << typeid(BackendType).name() << std::endl;
 
-  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(0)  == "0");
-  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(8)  == "0.00000000");
-  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(12) == "0.000000000000");
-  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(31) == "0.0000000000000000222222222222222");
+  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(std::streamsize { INT8_C(0) })  == "0");
+  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(std::streamsize { INT8_C(8) })  == "0.00000000");
+  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(std::streamsize { INT8_C(12) }) == "0.000000000000");
+  BOOST_TEST(my_stringify_via_top_level_number<BackendType>(std::streamsize { INT8_C(31) }) == "0.0000000000000000222222222222222");
+
+  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(std::streamsize { INT8_C(0) })  == "0");
+  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(std::streamsize { INT8_C(8) })  == "0.00000000");
+  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(std::streamsize { INT8_C(12) }) == "0.000000000000");
+  BOOST_TEST(my_stringify_via_str_and_backend_str<BackendType>(std::streamsize { INT8_C(31) }) == "0.0000000000000000222222222222222");
 }
 
 } // namespace local
@@ -62,7 +77,10 @@ auto main() -> int
 {
   local::test<boost::multiprecision::cpp_bin_float<32>>();
   local::test<boost::multiprecision::cpp_dec_float<32>>();
-  local::test<boost::multiprecision::cpp_double_fp_backend<double>>();
+  BOOST_IF_CONSTEXPR(std::numeric_limits<double>::digits >= 53)
+  {
+    local::test<boost::multiprecision::cpp_double_fp_backend<double>>();
+  }
 
   return boost::report_errors();
 }