CODEWITHSUNDEEP
iodstandard-library
Kile Kasmir Asmussen
Kile Kasmir Asmussen

Reputation: 310

Intercompatibility between std.stdio.File and std.stream.*

Is there any good way to turn a std.stdio.File into something that is an instance of a stream from std.stream?

Reason: I find myself wanting a generic logging utility working on streams, and I want to pass it std.stdio.stderr which is a std.stdio.File.

Upvotes: 1

Views: 153

Answers (2)

Colonel Thirty Two
Colonel Thirty Two

Reputation: 26579

Instead of the deprecated std.stream module, use ranges.

import std.stdio;
import std.range;
import std.algorithm;
import std.typecons;
import std.conv;

// Log levels
enum LEVEL {
    DEBUG,
    INFO,
    WARN
};
alias LogMsg = Tuple!(LEVEL, string); // Should be a struct, but I'm lazy

void main() {
    // Get a writer, which is an OutputRange
    auto writer = stderr.lockingTextWriter();

    // Some messages. Can be any InputRange, not just an array
    auto messages = [
        LogMsg(LEVEL.DEBUG, "Log message 1"),
        LogMsg(LEVEL.INFO, "Log message 2"),
        LogMsg(LEVEL.WARN, "Log message 3"),
    ];

    // Write each message to the writer
    put(writer, messages
        // transform LogMsg's into strings to write.
        // Bonus points: use chain instead of ~ to avoid allocation
        .map!(msg => msg[0].to!string ~ ": " ~ msg[1] ~ "\n")
    );
}

Upvotes: 4

Kozzi11
Kozzi11

Reputation: 2413

you can use derr from cstream.

example:

import std.stream;
import std.cstream;

void main() {
    ubyte[] data = cast(ubyte[])"someData";
    OutputStream stream = derr;
    stream.write(data);
}

Btw. there is a logging module in D standard lib

Upvotes: 2

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