vec4 constructor is not constexpr

out of these 4, all work except the vec4 one, which complains:
error: call to non-constexpr function 'glm::vec<4, T, Q>::vec(T, T, T, T) [with T = float; glm::qualifier Q = (glm::qualifier)0]

static_assert(glm::vec1(1.0f).x > 0.0f);
static_assert(glm::vec2(1.0f, 1.0f).x > 0.0f);
static_assert(glm::vec3(1.0f, 1.0f, 1.0f).x > 0.0f);
static_assert(glm::vec4(1.0f, 1.0f, 1.0f, 1.0f).x > 0.0f);