Home > Article > Backend Development > Beyond `if` Statements: Where Else Can a Type with an Explicit `bool` Conversion Be Used Without Casting?
Your class defines an explicit conversion to bool, enabling you to use its instance 't' directly in conditional statements. However, this explicit conversion poses the question: where else can 't' be used as a bool without a cast?
Contextual Conversion Scenarios
The C standard specifies four main scenarios where a value can be contextually converted to bool:
Statements:
if, while, for, do-while statements
<code class="cpp">if (t) /* statement */;</code>
Expressions:
Negation (!), logical AND (&&), logical OR (||), ternary operator (?)
<code class="cpp">!t t && t2</code>
Compile-Time Tests:
static_assert, noexcept, explicit, if constexpr (requires constexpr conversion operator)
<code class="cpp">static_assert(t); noexcept(t)</code>
Algorithms and Concepts:
NullablePointer, predicate or comparator arguments in STL algorithms
<code class="cpp">NullablePointer T std::remove_if(first, last, [&](auto){ return t; });</code>
Additional Notes:
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