[veg] remove whitespace in user-define literals ""_c and ""_v

This fixes the -Wdeprecated-literal-operator warning.

Author: ManifoldFR

include/proxsuite/linalg/veg/internal/dyn_index.hpp

@@ -259,7 +259,7 @@ struct binary_traits<Dyn, Fix<N>> : binary_traits<Dyn, Dyn>
 
 inline namespace literals {
 VEG_INLINE constexpr auto
-operator"" _v(unsigned long long n) VEG_NOEXCEPT->Dyn
+operator""_v(unsigned long long n) VEG_NOEXCEPT->Dyn
 {
   return isize(n);
 }

include/proxsuite/linalg/veg/internal/fix_index.hpp

@@ -326,7 +326,7 @@ namespace adl {
 inline namespace literals {
 template<char... Chars>
 VEG_INLINE constexpr auto
-operator"" _c() VEG_NOEXCEPT
+operator""_c() VEG_NOEXCEPT
 {
   return Fix<_detail::parse_int(
     _detail::char_seq<Chars...>::value, sizeof...(Chars), _detail::Error{})>{};