libstdc++: Check static assertions earlier in chrono::duration
This ensures that we fail a static assertion before giving any other
errors. Instantiating chrono::duration<int, chrono::seconds> will now
print this before the other errors caused by it:
error: static assertion failed: period must be a specialization of ratio
libstdc++-v3/ChangeLog:
* include/bits/chrono.h (duration): Check preconditions on
template arguments before using them.
diff --git a/libstdc++-v3/include/bits/chrono.h b/libstdc++-v3/include/bits/chrono.h
index 05987ca..cabf612 100644
--- a/libstdc++-v3/include/bits/chrono.h
+++ b/libstdc++-v3/include/bits/chrono.h
@@ -433,6 +433,11 @@
template<typename _Rep, typename _Period>
struct duration
{
+ static_assert(!__is_duration<_Rep>::value, "rep cannot be a duration");
+ static_assert(__is_ratio<_Period>::value,
+ "period must be a specialization of ratio");
+ static_assert(_Period::num > 0, "period must be positive");
+
private:
template<typename _Rep2>
using __is_float = treat_as_floating_point<_Rep2>;
@@ -478,11 +483,6 @@
using rep = _Rep;
using period = typename _Period::type;
- static_assert(!__is_duration<_Rep>::value, "rep cannot be a duration");
- static_assert(__is_ratio<_Period>::value,
- "period must be a specialization of ratio");
- static_assert(_Period::num > 0, "period must be positive");
-
// 20.11.5.1 construction / copy / destroy
constexpr duration() = default;
