Compiler diagnostic reference — C++, Rust and Go — DedSec Project

no matching function for call

Meaning

Overload resolution cannot find a function accepting the supplied arguments. Read the rejected candidate signatures, including argument count, order, namespace, constness, references and template constraints.

Reproducible example

#include <iostream>
#include <string_view>
void repeat(std::string_view text, int count) {
    for (int i=0; i<count; ++i) std::cout << text << '\n';
}
int main() {
    // repeat(2, "hi"); // wrong argument order
    repeat("hi", 2);
}

Build using g++ -std=c++17 -Wall -Wextra -pedantic example.cpp -o example && ./example. The repaired program prints hi twice. Uncomment the invalid call and compile again to inspect the diagnostic.

Investigate in order

First compare argument number and position against the declaration. Then check whether conversions are allowed. Non-const references cannot bind to arbitrary temporaries, while const references often can. For templates inspect deduction failure and constraints rather than guessing type arguments. If the signature appears correct, confirm the actual included header and namespace.

Lab

Create an overload accepting only std::string_view that delegates to repeat(text, 1). Verify both overloads. Next try repeat("hi", 2.5) with -Wconversion -Werror and observe the narrowing warning. Keep the original failing call as a compile-fail regression test.

Evidence

Record compiler version, build flags, expected function signature, actual candidate list, and the smallest change that resolves the mismatch. Avoid casts that merely suppress the type error without proving the API contract.

use of deleted function

Language / environment: C++

Meaning

An operation requires a method that was deleted or cannot be generated.

Repair

Review ownership, copying and moving; avoid copying unique_ptr values.

cargo: failed to select a version

Language / environment: Rust

Meaning

Dependency version constraints cannot be resolved.

Repair

Inspect Cargo.toml/Cargo.lock and supported versions; avoid blind updates.

cannot use X as Y in argument

Language / environment: Go

Meaning

A value does not satisfy an expected Go argument type.

Repair

Read the actual type, interface contract and conversion requirements.

imported and not used

Language / environment: Go

Meaning

The compiler rejects unused imports.

Repair

Remove unused imports, or use their declarations deliberately.