Replace boost::filesystem::load_string_file with own implementation

boost::filesystem::load_string_file was removed in boost 1.84

src/linkahead/utility.cpp

@@ -19,20 +19,21 @@
  *
  */
 #include "linkahead/utility.h"
-#include "linkahead/data_type.h"              // for AtomicDataType, atomicdatatype_names
-#include "linkahead/entity.h"                 // for Importance, Role, importance_names
 #include <boost/beast/core/detail/base64.hpp> // for encoded_size
 #include <boost/beast/core/detail/base64.ipp> // for encode
-#include <boost/filesystem/string_file.hpp>   // for load_string_file
 #include <boost/json/stream_parser.hpp>       // for stream_parser
 #include <boost/json/value.hpp>               // for value
 #include <cassert>                            // for assert
-#include <map>                                // for map, operator!=, _Rb_tree_const_iterator
-#include <memory>                             // for allocator, unique_ptr
-#include <stdexcept>                          // for logic_error
+#include <cstdint>                            // for uintmax_t
+#include <limits>                             // for numeric_limits
+#include <map>                                // for map, _Rb_tree_const_it...
+#include <memory>                             // for shared_ptr, allocator
+#include <stdexcept>                          // for out_of_range, length_e...
 #include <type_traits>                        // for underlying_type_t
 #include <typeinfo>                           // for type_info
-#include <utility>                            // for pair
+#include <utility>                            // for pair, move
+#include "linkahead/data_type.h"              // for AtomicDataType, atomic...
+#include "linkahead/entity.h"                 // for Importance, Role, impo...
 
 namespace linkahead::utility {
 
@@ -106,7 +107,20 @@ template <> auto getEnumValueFromName<Role>(const std::string &name) -> Role {
 
 auto load_string_file(const path &file_path) -> std::string {
   std::string result;
-  boost::filesystem::load_string_file(file_path.string(), result);
+
+  // adapted from boost::filesystem::load_string_file, which was removed in 1.84
+  std::ifstream file;
+  file.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+  file.open(file_path, std::ios_base::binary);
+  const std::uintmax_t sz = std::filesystem::file_size(file_path);
+  if ((sz > static_cast<std::uintmax_t>((std::numeric_limits<std::streamsize>::max)()))) {
+    throw(std::length_error("File size exceeds max read size"));
+  }
+  result.resize(static_cast<std::size_t>(sz), '\0');
+  if (sz > 0U) {
+    file.read(result.data(), static_cast<std::streamsize>(sz));
+  }
+
   return result;
 }