Why does `Output::Print(\'Hello World\')` print \'True\' instead of \'Hello World\'?

String Literal Overload Conflict: Bool vs. std::string

In C , class methods can be overloaded to accept different parameter types. However, sometimes a string literal may unexpectedly matched the boolean type overload instead of the expected std::string overload.

Problem description:

Suppose we have an Output class defined as follows:

<code class="cpp">class Output
{
public:
    static void Print(bool value)
    {
        std::cout <p>When calling Output::Print("Hello World "), the output result is "True" instead of the expected "Hello World". </p>
<p><strong>Problem analysis: </strong></p>
<p>Although we defined the std::string overload, "Hello World" is actually a character array constant that can be implicitly converted to bool. The compiler prefers this standard conversion over the user-defined std::string conversion constructor. </p>
<p>According to the C standard (§13.3.3.2/2), standard conversion orders prevail over user-defined conversion orders. Therefore, the compiler chooses the bool overload because it has better conversion order. </p>
<p><strong>Workaround: </strong></p>
<p>In order to explicitly call the std::string overload, we need to explicitly pass "Hello World" as std::string: </p> <pre class="brush:php;toolbar:false"><code class="cpp">Output::Print(std::string("Hello World"));</code>

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