Change length argument type to size_t

src/solvers/refinement/string_constraint_generator.h

@@ -373,7 +373,7 @@ exprt get_numeric_value_from_character(
 
 size_t max_printed_string_length(const typet &type, unsigned long ul_radix);
 
-std::string utf16_constant_array_to_java(
-  const array_exprt &arr, unsigned length);
+std::string
+utf16_constant_array_to_java(const array_exprt &arr, std::size_t length);
 
 #endif

src/solvers/refinement/string_constraint_generator_format.cpp

@@ -417,8 +417,8 @@ exprt string_constraint_generatort::add_axioms_for_format(
 /// \param length: an unsigned value representing the length of the array
 /// \return String of length `length` represented by the array assuming each
 ///   field in `arr` represents a character.
-std::string utf16_constant_array_to_java(
-  const array_exprt &arr, unsigned int length)
+std::string
+utf16_constant_array_to_java(const array_exprt &arr, std::size_t length)
 {
   std::wstring out(length, '?');
   unsigned int c;

src/solvers/refinement/string_refinement.cpp

@@ -858,7 +858,7 @@ static std::string string_of_array(const array_exprt &arr)
       return std::string("");
 
   exprt size_expr=to_array_type(arr.type()).size();
-  auto n = numeric_cast_v<unsigned>(size_expr);
+  auto n = numeric_cast_v<std::size_t>(size_expr);
   return utf16_constant_array_to_java(arr, n);
 }