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    <p>GCC does not provide such a mechanism as you want. However you will not need it if you are able to refactor your code somewhat as illustrated in the following program. (I have filled in a few gaps so as to give us a compilable example):</p> <pre><code>#include &lt;type_traits&gt; #include &lt;vector&gt; template&lt;typename ContainerType&gt; struct is_container { static bool const value = false; }; template&lt;&gt; struct is_container&lt;std::vector&lt;int&gt;&gt; { static bool const value = true; }; template&lt;typename ContainerType&gt; struct IsContainerCheck // : is_container&lt;ContainerType&gt; &lt;- Uneccessary { static_assert(is_container&lt;ContainerType&gt;::value, "Type is not a container model"); }; namespace _check_concept { template&lt;typename ResultType&gt; struct run { constexpr static int apply() { return (IsContainerCheck&lt;ResultType&gt;(),0); } }; // No such specialization is necessary. Delete it. // template&lt;&gt; // struct run&lt;true_t&gt; { // constexpr static int apply() { // return 0; // } //}; } using namespace _check_concept; int main(int argc, char **argv) { auto verdict0 = run&lt;std::vector&lt;int&gt;&gt;::apply(); (void)verdict0; // The following line will static_assert: "Type is not a container model" auto verdict1 = run&lt;float&gt;::apply(); (void)verdict1; return 0; } </code></pre> <p>In your specialization <code>_check_concept::struct run&lt;true_t&gt;</code> I presume that <code>true_t</code> is <em>not</em> an alias or equivalent of <code>std::true_type</code>, but rather just a place-holder for <em>some <code>ResultType</code> that is a container type</em>. As the test program shows, no such specialization is now necessary, because <code>IsContainerCheck&lt;ResultType&gt;()</code> will <code>static_assert</code>, or not, depending on <code>ResultType</code>, in the unspecialized <code>run&lt;ResultType&gt;::apply()</code>.</p>
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    1. POIs there a way to print a constexpr string during compiletime?
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    1. USMike Kinghan
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    1. POIs there a way to print a constexpr string during compiletime?
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    1. COI would expect the check to happen as soon as the template is instantiated, which does not necessarily require that any object is constructed.
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    2. COQuite so. Just edited to try and express that.
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    3. COI'll just scratch that para. I thought I had a gotcha that necessitated a constructor call on the wrapper but I can't make it simple, so it's bound to something wrong with my code.
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