Raw pointers in C++ implementation

[zigzag312]

Rules says no unsafe code blocks. Raw pointers are what other languages consider unsafe. Since smart pointers are available in modern C++, wouldn't replacing raw pointers with smart pointers make the most sense?

[jinyus]

I'm not opposed to that but I'm no C++ expert so that will have to be contributed.

[zigzag312]

My knowledge of C++ is rather light as well. I would change RelatedPosts struct like this:

struct RelatedPosts
{
    std::shared_ptr<std::string const> _id;
    std::shared_ptr<std::vector<std::string> const> tags;
    std::array<std::shared_ptr<Post const>, TOPN> related;
};

But then the use of shared_ptr needs to propagate all the way back to the input posts vector. Probably best to wait for someone with more C++ experience to chime in, so we don't create a Frankenstein's monster of an implementation.

[cyrusmsk]

Btw how differ pointers in Nim, Go and Rust from C++ in that struct?

Go

type RelatedPosts struct {
	ID      string      `json:"_id"`
	Tags    *[]string   `json:"tags"`
	Related [topN]*Post `json:"related"`
} 

Nim

RelatedPosts = ref object
    `"_id"`: string
    tags : ref seq[string]
    related: array[N, ptr Post]

Rust

struct RelatedPosts<'a> {
    #[serde(rename = "_id")]
    id: &'a str,
    tags: &'a [&'a str],
    related: Vec<&'a Post<'a>>,
}

all three are using pointers for tags array and post.. is it safe approach?

[zigzag312]

I think Go's default pointers are managed by GC and are therefore safe.

Rust pointers have lifetime 'a attached, so they are also safe?

I don't know about Nim.

[jinyus]

According to https://nim-lang.github.io/Nim/tut1.html#advanced-types-reference-and-pointer-types, ref is GC managed and ptr is not, thus unsafe. That will have to be addressed. @michaelsbradleyjr