feat: Optimize to_string

[mertcanaltin]

optimize to_string

[mertcanaltin]

this step worked in my local environment .

macOS (Installation) / macos-build (OFF, macos-15) (pull_request)

➜  ada git:(mert/fix/warnings) cmake --build build -j=3
[ 16%] Built target simdjson
[ 16%] Built target ada
[ 16%] Built target gtest
[ 21%] Built target gtest_main
[ 32%] Built target basic_fuzzer
[ 35%] Built target ada-singleheader-lib
[ 37%] Built target ada-singleheader-files
[ 43%] Built target wpt_urlpattern_tests
[ 48%] Built target wpt_url_tests
[ 54%] Built target url_components
[ 59%] Built target ada_c
[ 70%] Built target basic_tests
[ 70%] Built target from_file_tests
[ 75%] Built target url_search_params
[ 91%] Built target demo
[ 91%] Built target demo_no_url_pattern
[100%] Built target cdemo
➜  ada git:(mert/fix/warnings) 

[lemire]

This changes the API, and if we do change the API, we might as well return a std::string_view instance. This will improve the efficiency of the code.

Note that there is nothing wrong with the existing code, except for the fact that it creates a new instance of an std::string which is wasteful (which the new code is likely to do as well).

[mertcanaltin]

Thanks. I've applied that change.

[lemire]

I don't understand the change here, can you elaborate on your purpose?

[mertcanaltin]

warning: variable 'internal_input' is not initialized [cppcoreguidelines-init-variables]
   31 |   std::string_view internal_input;
      |                    ^           

compiler was warning about an uninitialized variable. I tried to fix this warning by initializing internal_input with an empty string_view ({}), following the C++ Core Guidelines to initialize every variable

[lemire]

@mertcanaltin Can you elaborate on why internal_input is uninitialized after... this line...

std::string href_from_file(std::string_view input) {
  std::string tmp_buffer;
  std::string_view internal_input;
  ...
}

This looks like textbook C++:

class A {...};

void myfunc() {
  A a; // call default constructor of A
}

Please don't argue from the warning message of some tool. There is an endless stream of warnings one can get from static analyzers.

The std::string_view class has a default constructor.

[mertcanaltin]

You are absolutely right, std::string_view has a default constructor and internal_input is indeed created by default.

intention behind std::string_view internal_input{}; was primarily to explicitly state the initial (empty) state of the variable and satisfy the cppcoreguidelines-init-variables static analysis check, which prefers explicit initialization even if a default constructor is present. This was a stylistic choice for clarity and to silence this particular analyzer warning, rather than to address an actual runtime error, but I agree with what you say that this is an tool (clang-tidy) tool's warning.

here I get the code back thank you very much again.