In C++, you can set the default at the same time as you declare the member variable, meaning the three things (variable type, variable name and variable default) are in exactly the same place in the code on the same line.
In Rust, you can't do this, you need to implement new() or default() (or manually specify all field items when declaring the struct), which is normally in another place in the code, so you have tightly-coupled code in two places, which is as bad as C++ headers and implementation files which is what a lot of Rust evangelists seem to complain about on here about C++ (it's a valid complaint, but I don't think Rust completely gets it right, as is complicates / makes things more verbose in other ways like this one).
In C++, you can set the default at the same time as you declare the member variable, meaning the three things (variable type, variable name and variable default) are in exactly the same place in the code on the same line.
In Rust, you can't do this, you need to implement new() or default() (or manually specify all field items when declaring the struct), which is normally in another place in the code, so you have tightly-coupled code in two places, which is as bad as C++ headers and implementation files which is what a lot of Rust evangelists seem to complain about on here about C++ (it's a valid complaint, but I don't think Rust completely gets it right, as is complicates / makes things more verbose in other ways like this one).